diff --git a/bin/doctrine-dbal.php b/bin/doctrine-dbal.php
index f3e064ffd62..76bed1a6701 100644
--- a/bin/doctrine-dbal.php
+++ b/bin/doctrine-dbal.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 use Doctrine\DBAL\Tools\Console\ConsoleRunner;
 use Symfony\Component\Console\Helper\HelperSet;
 
diff --git a/lib/Doctrine/DBAL/Cache/ArrayStatement.php b/lib/Doctrine/DBAL/Cache/ArrayStatement.php
index ef9bf7bff25..cd2984c2b73 100644
--- a/lib/Doctrine/DBAL/Cache/ArrayStatement.php
+++ b/lib/Doctrine/DBAL/Cache/ArrayStatement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Cache;
 
 use ArrayIterator;
diff --git a/lib/Doctrine/DBAL/Cache/CacheException.php b/lib/Doctrine/DBAL/Cache/CacheException.php
index 636c948a616..5ad3d3f7aac 100644
--- a/lib/Doctrine/DBAL/Cache/CacheException.php
+++ b/lib/Doctrine/DBAL/Cache/CacheException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Cache;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Cache/QueryCacheProfile.php b/lib/Doctrine/DBAL/Cache/QueryCacheProfile.php
index 9433f982fc5..b32fdf6c87e 100644
--- a/lib/Doctrine/DBAL/Cache/QueryCacheProfile.php
+++ b/lib/Doctrine/DBAL/Cache/QueryCacheProfile.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Cache;
 
 use Doctrine\Common\Cache\Cache;
diff --git a/lib/Doctrine/DBAL/Cache/ResultCacheStatement.php b/lib/Doctrine/DBAL/Cache/ResultCacheStatement.php
index 527c730a2fb..49906264885 100644
--- a/lib/Doctrine/DBAL/Cache/ResultCacheStatement.php
+++ b/lib/Doctrine/DBAL/Cache/ResultCacheStatement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Cache;
 
 use ArrayIterator;
diff --git a/lib/Doctrine/DBAL/ColumnCase.php b/lib/Doctrine/DBAL/ColumnCase.php
index c78ad372e65..0edede03348 100644
--- a/lib/Doctrine/DBAL/ColumnCase.php
+++ b/lib/Doctrine/DBAL/ColumnCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 /**
diff --git a/lib/Doctrine/DBAL/Configuration.php b/lib/Doctrine/DBAL/Configuration.php
index 06b3603ed1e..7cbca89a26a 100644
--- a/lib/Doctrine/DBAL/Configuration.php
+++ b/lib/Doctrine/DBAL/Configuration.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 use Doctrine\Common\Cache\Cache;
diff --git a/lib/Doctrine/DBAL/Connection.php b/lib/Doctrine/DBAL/Connection.php
index a2354bbb842..1057ea9bb98 100644
--- a/lib/Doctrine/DBAL/Connection.php
+++ b/lib/Doctrine/DBAL/Connection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 use Closure;
diff --git a/lib/Doctrine/DBAL/ConnectionException.php b/lib/Doctrine/DBAL/ConnectionException.php
index d3d11bc6743..94207b01bd9 100644
--- a/lib/Doctrine/DBAL/ConnectionException.php
+++ b/lib/Doctrine/DBAL/ConnectionException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 class ConnectionException extends DBALException
diff --git a/lib/Doctrine/DBAL/Connections/MasterSlaveConnection.php b/lib/Doctrine/DBAL/Connections/MasterSlaveConnection.php
index 6ef3d034438..3174ed1a17d 100644
--- a/lib/Doctrine/DBAL/Connections/MasterSlaveConnection.php
+++ b/lib/Doctrine/DBAL/Connections/MasterSlaveConnection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Connections;
 
 use Doctrine\Common\EventManager;
diff --git a/lib/Doctrine/DBAL/DBALException.php b/lib/Doctrine/DBAL/DBALException.php
index 87a03daf595..e909980534b 100644
--- a/lib/Doctrine/DBAL/DBALException.php
+++ b/lib/Doctrine/DBAL/DBALException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 use Doctrine\DBAL\Driver\DriverException as DriverExceptionInterface;
diff --git a/lib/Doctrine/DBAL/Driver.php b/lib/Doctrine/DBAL/Driver.php
index 8a80d4a428a..5c7512b03f1 100644
--- a/lib/Doctrine/DBAL/Driver.php
+++ b/lib/Doctrine/DBAL/Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Driver/AbstractDB2Driver.php b/lib/Doctrine/DBAL/Driver/AbstractDB2Driver.php
index c6e0565343a..f283ed163ea 100644
--- a/lib/Doctrine/DBAL/Driver/AbstractDB2Driver.php
+++ b/lib/Doctrine/DBAL/Driver/AbstractDB2Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Driver/AbstractDriverException.php b/lib/Doctrine/DBAL/Driver/AbstractDriverException.php
index d9af92d1744..59c08090a4c 100644
--- a/lib/Doctrine/DBAL/Driver/AbstractDriverException.php
+++ b/lib/Doctrine/DBAL/Driver/AbstractDriverException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Exception;
diff --git a/lib/Doctrine/DBAL/Driver/AbstractMySQLDriver.php b/lib/Doctrine/DBAL/Driver/AbstractMySQLDriver.php
index c46ddc63dd7..9229b29bfef 100644
--- a/lib/Doctrine/DBAL/Driver/AbstractMySQLDriver.php
+++ b/lib/Doctrine/DBAL/Driver/AbstractMySQLDriver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Driver/AbstractOracleDriver.php b/lib/Doctrine/DBAL/Driver/AbstractOracleDriver.php
index dcbaaf097f7..e9e1cce5382 100644
--- a/lib/Doctrine/DBAL/Driver/AbstractOracleDriver.php
+++ b/lib/Doctrine/DBAL/Driver/AbstractOracleDriver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Driver/AbstractPostgreSQLDriver.php b/lib/Doctrine/DBAL/Driver/AbstractPostgreSQLDriver.php
index bdfd6cd894b..41a9f058e9a 100644
--- a/lib/Doctrine/DBAL/Driver/AbstractPostgreSQLDriver.php
+++ b/lib/Doctrine/DBAL/Driver/AbstractPostgreSQLDriver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Driver/AbstractSQLAnywhereDriver.php b/lib/Doctrine/DBAL/Driver/AbstractSQLAnywhereDriver.php
index f93b576e202..a4c45ccaa23 100644
--- a/lib/Doctrine/DBAL/Driver/AbstractSQLAnywhereDriver.php
+++ b/lib/Doctrine/DBAL/Driver/AbstractSQLAnywhereDriver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Driver/AbstractSQLServerDriver.php b/lib/Doctrine/DBAL/Driver/AbstractSQLServerDriver.php
index 280f72544e0..dc22ebd5bb1 100644
--- a/lib/Doctrine/DBAL/Driver/AbstractSQLServerDriver.php
+++ b/lib/Doctrine/DBAL/Driver/AbstractSQLServerDriver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Driver/AbstractSQLiteDriver.php b/lib/Doctrine/DBAL/Driver/AbstractSQLiteDriver.php
index 582f7cae20a..abb7db13153 100644
--- a/lib/Doctrine/DBAL/Driver/AbstractSQLiteDriver.php
+++ b/lib/Doctrine/DBAL/Driver/AbstractSQLiteDriver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Driver/Connection.php b/lib/Doctrine/DBAL/Driver/Connection.php
index 14dbb54f31f..acae0b66f9a 100644
--- a/lib/Doctrine/DBAL/Driver/Connection.php
+++ b/lib/Doctrine/DBAL/Driver/Connection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/DriverException.php b/lib/Doctrine/DBAL/Driver/DriverException.php
index 79480ac72be..c95609712bb 100644
--- a/lib/Doctrine/DBAL/Driver/DriverException.php
+++ b/lib/Doctrine/DBAL/Driver/DriverException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Throwable;
diff --git a/lib/Doctrine/DBAL/Driver/ExceptionConverterDriver.php b/lib/Doctrine/DBAL/Driver/ExceptionConverterDriver.php
index 9b79e240c4e..344eca14841 100644
--- a/lib/Doctrine/DBAL/Driver/ExceptionConverterDriver.php
+++ b/lib/Doctrine/DBAL/Driver/ExceptionConverterDriver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 /**
diff --git a/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Connection.php b/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Connection.php
index 4f88decbd69..ef4dd3546d9 100644
--- a/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Connection.php
+++ b/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Connection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=0);
+
 namespace Doctrine\DBAL\Driver\IBMDB2;
 
 use Doctrine\DBAL\Driver\Connection;
diff --git a/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Driver.php b/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Driver.php
index fe79fe6bd37..b6b922d913f 100644
--- a/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Driver.php
+++ b/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\IBMDB2;
 
 use Doctrine\DBAL\Driver\AbstractDB2Driver;
diff --git a/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Exception.php b/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Exception.php
index cb8e626fcdb..eea9cc1c9e2 100644
--- a/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Exception.php
+++ b/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Exception.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\IBMDB2;
 
 use Doctrine\DBAL\Driver\AbstractDriverException;
diff --git a/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Statement.php b/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Statement.php
index d829c7c79ee..0096feff73c 100644
--- a/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Statement.php
+++ b/lib/Doctrine/DBAL/Driver/IBMDB2/DB2Statement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\IBMDB2;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/Mysqli/Driver.php b/lib/Doctrine/DBAL/Driver/Mysqli/Driver.php
index 1166e8d4c2e..52a61293fea 100644
--- a/lib/Doctrine/DBAL/Driver/Mysqli/Driver.php
+++ b/lib/Doctrine/DBAL/Driver/Mysqli/Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\Mysqli;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/Mysqli/MysqliConnection.php b/lib/Doctrine/DBAL/Driver/Mysqli/MysqliConnection.php
index 789b2c8b4ba..0b28b2cae50 100644
--- a/lib/Doctrine/DBAL/Driver/Mysqli/MysqliConnection.php
+++ b/lib/Doctrine/DBAL/Driver/Mysqli/MysqliConnection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\Mysqli;
 
 use Doctrine\DBAL\Driver\Connection;
@@ -47,7 +49,7 @@ class MysqliConnection implements Connection, PingableConnection, ServerInfoAwar
      */
     public function __construct(array $params, $username, $password, array $driverOptions = [])
     {
-        $port = $params['port'] ?? ini_get('mysqli.default_port');
+        $port = $params['port'] ?? (int) ini_get('mysqli.default_port');
 
         // Fallback to default MySQL port if not given.
         if (! $port) {
@@ -55,9 +57,9 @@ public function __construct(array $params, $username, $password, array $driverOp
         }
 
         $socket = $params['unix_socket'] ?? ini_get('mysqli.default_socket');
-        $dbname = $params['dbname'] ?? null;
+        $dbname = $params['dbname'] ?? '';
 
-        $flags = $driverOptions[static::OPTION_FLAGS] ?? null;
+        $flags = $driverOptions[static::OPTION_FLAGS] ?? 0;
 
         $this->conn = mysqli_init();
 
diff --git a/lib/Doctrine/DBAL/Driver/Mysqli/MysqliException.php b/lib/Doctrine/DBAL/Driver/Mysqli/MysqliException.php
index 1fa0c900fbd..b779bc40457 100644
--- a/lib/Doctrine/DBAL/Driver/Mysqli/MysqliException.php
+++ b/lib/Doctrine/DBAL/Driver/Mysqli/MysqliException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\Mysqli;
 
 use Doctrine\DBAL\Driver\AbstractDriverException;
diff --git a/lib/Doctrine/DBAL/Driver/Mysqli/MysqliStatement.php b/lib/Doctrine/DBAL/Driver/Mysqli/MysqliStatement.php
index 2faed0afb3c..fed098f3c09 100644
--- a/lib/Doctrine/DBAL/Driver/Mysqli/MysqliStatement.php
+++ b/lib/Doctrine/DBAL/Driver/Mysqli/MysqliStatement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\Mysqli;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/OCI8/Driver.php b/lib/Doctrine/DBAL/Driver/OCI8/Driver.php
index edda32d6a56..c3d88d3d801 100644
--- a/lib/Doctrine/DBAL/Driver/OCI8/Driver.php
+++ b/lib/Doctrine/DBAL/Driver/OCI8/Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\OCI8;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/OCI8/OCI8Connection.php b/lib/Doctrine/DBAL/Driver/OCI8/OCI8Connection.php
index 20fb9d4b2e6..8a75d27f62e 100644
--- a/lib/Doctrine/DBAL/Driver/OCI8/OCI8Connection.php
+++ b/lib/Doctrine/DBAL/Driver/OCI8/OCI8Connection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\OCI8;
 
 use Doctrine\DBAL\Driver\Connection;
@@ -180,7 +182,7 @@ public function beginTransaction() : void
     public function commit() : void
     {
         if (! oci_commit($this->dbh)) {
-            throw OCI8Exception::fromErrorInfo($this->errorInfo());
+            throw OCI8Exception::fromErrorInfo(oci_error($this->dbh));
         }
 
         $this->executeMode = OCI_COMMIT_ON_SUCCESS;
@@ -192,7 +194,7 @@ public function commit() : void
     public function rollBack() : void
     {
         if (! oci_rollback($this->dbh)) {
-            throw OCI8Exception::fromErrorInfo($this->errorInfo());
+            throw OCI8Exception::fromErrorInfo(oci_error($this->dbh));
         }
 
         $this->executeMode = OCI_COMMIT_ON_SUCCESS;
diff --git a/lib/Doctrine/DBAL/Driver/OCI8/OCI8Exception.php b/lib/Doctrine/DBAL/Driver/OCI8/OCI8Exception.php
index af3a9d1a7a9..bdb64347a6a 100644
--- a/lib/Doctrine/DBAL/Driver/OCI8/OCI8Exception.php
+++ b/lib/Doctrine/DBAL/Driver/OCI8/OCI8Exception.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\OCI8;
 
 use Doctrine\DBAL\Driver\AbstractDriverException;
diff --git a/lib/Doctrine/DBAL/Driver/OCI8/OCI8Statement.php b/lib/Doctrine/DBAL/Driver/OCI8/OCI8Statement.php
index 3fe3b61d136..8949ff2b132 100644
--- a/lib/Doctrine/DBAL/Driver/OCI8/OCI8Statement.php
+++ b/lib/Doctrine/DBAL/Driver/OCI8/OCI8Statement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\OCI8;
 
 use Doctrine\DBAL\DBALException;
@@ -300,7 +302,7 @@ public function bindParam($column, &$variable, $type = ParameterType::STRING, $l
             $length ?? -1,
             $this->convertParameterType($type)
         )) {
-            throw OCI8Exception::fromErrorInfo($this->errorInfo());
+            throw OCI8Exception::fromErrorInfo(oci_error($this->_sth));
         }
     }
 
@@ -392,7 +394,7 @@ public function execute($params = null) : void
 
         $ret = @oci_execute($this->_sth, $this->_conn->getExecuteMode());
         if (! $ret) {
-            throw OCI8Exception::fromErrorInfo($this->errorInfo());
+            throw OCI8Exception::fromErrorInfo(oci_error($this->_sth));
         }
 
         $this->result = true;
diff --git a/lib/Doctrine/DBAL/Driver/PDOConnection.php b/lib/Doctrine/DBAL/Driver/PDOConnection.php
index d9cbb681c8c..bc9128e1eb3 100644
--- a/lib/Doctrine/DBAL/Driver/PDOConnection.php
+++ b/lib/Doctrine/DBAL/Driver/PDOConnection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use PDO;
diff --git a/lib/Doctrine/DBAL/Driver/PDOException.php b/lib/Doctrine/DBAL/Driver/PDOException.php
index 277d7a62500..47f12e7834c 100644
--- a/lib/Doctrine/DBAL/Driver/PDOException.php
+++ b/lib/Doctrine/DBAL/Driver/PDOException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 /**
diff --git a/lib/Doctrine/DBAL/Driver/PDOMySql/Driver.php b/lib/Doctrine/DBAL/Driver/PDOMySql/Driver.php
index dcd4ff51895..5e9cd33ad6e 100644
--- a/lib/Doctrine/DBAL/Driver/PDOMySql/Driver.php
+++ b/lib/Doctrine/DBAL/Driver/PDOMySql/Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\PDOMySql;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/PDOOracle/Driver.php b/lib/Doctrine/DBAL/Driver/PDOOracle/Driver.php
index f1239eafbd4..79dd059a59f 100644
--- a/lib/Doctrine/DBAL/Driver/PDOOracle/Driver.php
+++ b/lib/Doctrine/DBAL/Driver/PDOOracle/Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\PDOOracle;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/PDOPgSql/Driver.php b/lib/Doctrine/DBAL/Driver/PDOPgSql/Driver.php
index f77f967ae47..75f0e167f1d 100644
--- a/lib/Doctrine/DBAL/Driver/PDOPgSql/Driver.php
+++ b/lib/Doctrine/DBAL/Driver/PDOPgSql/Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\PDOPgSql;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/PDOSqlite/Driver.php b/lib/Doctrine/DBAL/Driver/PDOSqlite/Driver.php
index 7c960ab3e14..db46ea8f5fe 100644
--- a/lib/Doctrine/DBAL/Driver/PDOSqlite/Driver.php
+++ b/lib/Doctrine/DBAL/Driver/PDOSqlite/Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\PDOSqlite;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Connection.php b/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Connection.php
index 803ab9e022f..34b7458133d 100644
--- a/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Connection.php
+++ b/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Connection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\PDOSqlsrv;
 
 use Doctrine\DBAL\Driver\PDOConnection;
diff --git a/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Driver.php b/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Driver.php
index 6d6c4844d57..9ef35eb0243 100644
--- a/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Driver.php
+++ b/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\PDOSqlsrv;
 
 use Doctrine\DBAL\Driver\AbstractSQLServerDriver;
diff --git a/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Statement.php b/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Statement.php
index 2844a682697..1507c4e45a6 100644
--- a/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Statement.php
+++ b/lib/Doctrine/DBAL/Driver/PDOSqlsrv/Statement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\PDOSqlsrv;
 
 use Doctrine\DBAL\Driver\PDOStatement;
diff --git a/lib/Doctrine/DBAL/Driver/PDOStatement.php b/lib/Doctrine/DBAL/Driver/PDOStatement.php
index c89507d0e79..b3b252a41f4 100644
--- a/lib/Doctrine/DBAL/Driver/PDOStatement.php
+++ b/lib/Doctrine/DBAL/Driver/PDOStatement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\DBALException;
@@ -10,6 +12,7 @@
 use const E_USER_DEPRECATED;
 use function array_slice;
 use function assert;
+use function count;
 use function func_get_args;
 use function is_array;
 use function sprintf;
@@ -80,10 +83,15 @@ public function bindValue($param, $value, $type = ParameterType::STRING) : void
      */
     public function bindParam($column, &$variable, $type = ParameterType::STRING, $length = null, $driverOptions = null) : void
     {
-        $type = $this->convertParamType($type);
+        $type            = $this->convertParamType($type);
+        $extraParameters = array_slice(func_get_args(), 3);
+
+        if (count($extraParameters) !== 0) {
+            $extraParameters[0] = $extraParameters[0] ?? 0;
+        }
 
         try {
-            $this->stmt->bindParam($column, $variable, $type, ...array_slice(func_get_args(), 3));
+            $this->stmt->bindParam($column, $variable, $type, ...$extraParameters);
         } catch (\PDOException $exception) {
             throw new PDOException($exception);
         }
diff --git a/lib/Doctrine/DBAL/Driver/PingableConnection.php b/lib/Doctrine/DBAL/Driver/PingableConnection.php
index 06bfb9a7f26..93e6168013e 100644
--- a/lib/Doctrine/DBAL/Driver/PingableConnection.php
+++ b/lib/Doctrine/DBAL/Driver/PingableConnection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 /**
diff --git a/lib/Doctrine/DBAL/Driver/ResultStatement.php b/lib/Doctrine/DBAL/Driver/ResultStatement.php
index 02422c50177..a00cbf00728 100644
--- a/lib/Doctrine/DBAL/Driver/ResultStatement.php
+++ b/lib/Doctrine/DBAL/Driver/ResultStatement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Traversable;
diff --git a/lib/Doctrine/DBAL/Driver/SQLAnywhere/Driver.php b/lib/Doctrine/DBAL/Driver/SQLAnywhere/Driver.php
index 9564dc2981d..535e5013a66 100644
--- a/lib/Doctrine/DBAL/Driver/SQLAnywhere/Driver.php
+++ b/lib/Doctrine/DBAL/Driver/SQLAnywhere/Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\SQLAnywhere;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereConnection.php b/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereConnection.php
index 1ba572dc6e0..d98cffcd9a8 100644
--- a/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereConnection.php
+++ b/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereConnection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\SQLAnywhere;
 
 use Doctrine\DBAL\Driver\Connection;
diff --git a/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereException.php b/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereException.php
index 0f8bc3e57e6..99e405585e3 100644
--- a/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereException.php
+++ b/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\SQLAnywhere;
 
 use Doctrine\DBAL\Driver\AbstractDriverException;
diff --git a/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereStatement.php b/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereStatement.php
index 8b02b9456bb..415be465041 100644
--- a/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereStatement.php
+++ b/lib/Doctrine/DBAL/Driver/SQLAnywhere/SQLAnywhereStatement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\SQLAnywhere;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/SQLSrv/Driver.php b/lib/Doctrine/DBAL/Driver/SQLSrv/Driver.php
index 848ab5eef91..d7e2ce62c34 100644
--- a/lib/Doctrine/DBAL/Driver/SQLSrv/Driver.php
+++ b/lib/Doctrine/DBAL/Driver/SQLSrv/Driver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\SQLSrv;
 
 use Doctrine\DBAL\Driver\AbstractSQLServerDriver;
diff --git a/lib/Doctrine/DBAL/Driver/SQLSrv/LastInsertId.php b/lib/Doctrine/DBAL/Driver/SQLSrv/LastInsertId.php
index 363b260950e..c76e66ff52e 100644
--- a/lib/Doctrine/DBAL/Driver/SQLSrv/LastInsertId.php
+++ b/lib/Doctrine/DBAL/Driver/SQLSrv/LastInsertId.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\SQLSrv;
 
 /**
diff --git a/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvConnection.php b/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvConnection.php
index 7fc1fa0fccc..2e4ac7da767 100644
--- a/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvConnection.php
+++ b/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvConnection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\SQLSrv;
 
 use Doctrine\DBAL\Driver\Connection;
diff --git a/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvException.php b/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvException.php
index 1c1e8c472d7..cbb4fa49e38 100644
--- a/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvException.php
+++ b/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\SQLSrv;
 
 use Doctrine\DBAL\Driver\AbstractDriverException;
diff --git a/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvStatement.php b/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvStatement.php
index f16e9b95ed0..5fe10f306e5 100644
--- a/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvStatement.php
+++ b/lib/Doctrine/DBAL/Driver/SQLSrv/SQLSrvStatement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver\SQLSrv;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Driver/ServerInfoAwareConnection.php b/lib/Doctrine/DBAL/Driver/ServerInfoAwareConnection.php
index c97a60fa356..d17b46c3b74 100644
--- a/lib/Doctrine/DBAL/Driver/ServerInfoAwareConnection.php
+++ b/lib/Doctrine/DBAL/Driver/ServerInfoAwareConnection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 /**
diff --git a/lib/Doctrine/DBAL/Driver/Statement.php b/lib/Doctrine/DBAL/Driver/Statement.php
index dca1ecda43e..8ad231fea10 100644
--- a/lib/Doctrine/DBAL/Driver/Statement.php
+++ b/lib/Doctrine/DBAL/Driver/Statement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\ParameterType;
diff --git a/lib/Doctrine/DBAL/Driver/StatementIterator.php b/lib/Doctrine/DBAL/Driver/StatementIterator.php
index 5246b38a448..98d3f08b3a9 100644
--- a/lib/Doctrine/DBAL/Driver/StatementIterator.php
+++ b/lib/Doctrine/DBAL/Driver/StatementIterator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Driver;
 
 use IteratorAggregate;
diff --git a/lib/Doctrine/DBAL/DriverManager.php b/lib/Doctrine/DBAL/DriverManager.php
index d44b314262e..33cbff22972 100644
--- a/lib/Doctrine/DBAL/DriverManager.php
+++ b/lib/Doctrine/DBAL/DriverManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 use Doctrine\Common\EventManager;
diff --git a/lib/Doctrine/DBAL/Event/ConnectionEventArgs.php b/lib/Doctrine/DBAL/Event/ConnectionEventArgs.php
index bb0ca886d99..8c40a3bfae3 100644
--- a/lib/Doctrine/DBAL/Event/ConnectionEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/ConnectionEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\Common\EventArgs;
diff --git a/lib/Doctrine/DBAL/Event/Listeners/MysqlSessionInit.php b/lib/Doctrine/DBAL/Event/Listeners/MysqlSessionInit.php
index 9e722904050..75fa6c3287f 100644
--- a/lib/Doctrine/DBAL/Event/Listeners/MysqlSessionInit.php
+++ b/lib/Doctrine/DBAL/Event/Listeners/MysqlSessionInit.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event\Listeners;
 
 use Doctrine\Common\EventSubscriber;
diff --git a/lib/Doctrine/DBAL/Event/Listeners/OracleSessionInit.php b/lib/Doctrine/DBAL/Event/Listeners/OracleSessionInit.php
index 19f2b3fd335..413f9c6df16 100644
--- a/lib/Doctrine/DBAL/Event/Listeners/OracleSessionInit.php
+++ b/lib/Doctrine/DBAL/Event/Listeners/OracleSessionInit.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event\Listeners;
 
 use Doctrine\Common\EventSubscriber;
diff --git a/lib/Doctrine/DBAL/Event/Listeners/SQLSessionInit.php b/lib/Doctrine/DBAL/Event/Listeners/SQLSessionInit.php
index ea63cab43d7..629e0f43cd8 100644
--- a/lib/Doctrine/DBAL/Event/Listeners/SQLSessionInit.php
+++ b/lib/Doctrine/DBAL/Event/Listeners/SQLSessionInit.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event\Listeners;
 
 use Doctrine\Common\EventSubscriber;
diff --git a/lib/Doctrine/DBAL/Event/SchemaAlterTableAddColumnEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaAlterTableAddColumnEventArgs.php
index 2f9edfea688..9799e9b4e59 100644
--- a/lib/Doctrine/DBAL/Event/SchemaAlterTableAddColumnEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaAlterTableAddColumnEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Event/SchemaAlterTableChangeColumnEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaAlterTableChangeColumnEventArgs.php
index 55661d5d307..33f2fac5fe9 100644
--- a/lib/Doctrine/DBAL/Event/SchemaAlterTableChangeColumnEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaAlterTableChangeColumnEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Event/SchemaAlterTableEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaAlterTableEventArgs.php
index 8f5f0ecf563..35258004fb9 100644
--- a/lib/Doctrine/DBAL/Event/SchemaAlterTableEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaAlterTableEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Event/SchemaAlterTableRemoveColumnEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaAlterTableRemoveColumnEventArgs.php
index 1bc9f590187..80daf00fe07 100644
--- a/lib/Doctrine/DBAL/Event/SchemaAlterTableRemoveColumnEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaAlterTableRemoveColumnEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Event/SchemaAlterTableRenameColumnEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaAlterTableRenameColumnEventArgs.php
index 911ea8b4ab6..49f7615c76e 100644
--- a/lib/Doctrine/DBAL/Event/SchemaAlterTableRenameColumnEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaAlterTableRenameColumnEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Event/SchemaColumnDefinitionEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaColumnDefinitionEventArgs.php
index 19d9f93a329..9e51b1038f0 100644
--- a/lib/Doctrine/DBAL/Event/SchemaColumnDefinitionEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaColumnDefinitionEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Event/SchemaCreateTableColumnEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaCreateTableColumnEventArgs.php
index 9d24b8b9049..312892daa7b 100644
--- a/lib/Doctrine/DBAL/Event/SchemaCreateTableColumnEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaCreateTableColumnEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Event/SchemaCreateTableEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaCreateTableEventArgs.php
index 954f77aa55a..7c05d1e8df1 100644
--- a/lib/Doctrine/DBAL/Event/SchemaCreateTableEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaCreateTableEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Event/SchemaDropTableEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaDropTableEventArgs.php
index 387049791d2..9d21bd35e0e 100644
--- a/lib/Doctrine/DBAL/Event/SchemaDropTableEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaDropTableEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Event/SchemaEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaEventArgs.php
index 0db0689c5ad..a5c152872b8 100644
--- a/lib/Doctrine/DBAL/Event/SchemaEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\Common\EventArgs;
diff --git a/lib/Doctrine/DBAL/Event/SchemaIndexDefinitionEventArgs.php b/lib/Doctrine/DBAL/Event/SchemaIndexDefinitionEventArgs.php
index 317f352b87a..bfbd8cfe619 100644
--- a/lib/Doctrine/DBAL/Event/SchemaIndexDefinitionEventArgs.php
+++ b/lib/Doctrine/DBAL/Event/SchemaIndexDefinitionEventArgs.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Event;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Events.php b/lib/Doctrine/DBAL/Events.php
index 5398d0f84c2..605afdb070a 100644
--- a/lib/Doctrine/DBAL/Events.php
+++ b/lib/Doctrine/DBAL/Events.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/ConnectionException.php b/lib/Doctrine/DBAL/Exception/ConnectionException.php
index e96a29191e4..4435379b87b 100644
--- a/lib/Doctrine/DBAL/Exception/ConnectionException.php
+++ b/lib/Doctrine/DBAL/Exception/ConnectionException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/ConstraintViolationException.php b/lib/Doctrine/DBAL/Exception/ConstraintViolationException.php
index 3959f39af95..7386f7f9a1e 100644
--- a/lib/Doctrine/DBAL/Exception/ConstraintViolationException.php
+++ b/lib/Doctrine/DBAL/Exception/ConstraintViolationException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/DatabaseObjectExistsException.php b/lib/Doctrine/DBAL/Exception/DatabaseObjectExistsException.php
index 7e0ba0299e9..e9c52067625 100644
--- a/lib/Doctrine/DBAL/Exception/DatabaseObjectExistsException.php
+++ b/lib/Doctrine/DBAL/Exception/DatabaseObjectExistsException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/DatabaseObjectNotFoundException.php b/lib/Doctrine/DBAL/Exception/DatabaseObjectNotFoundException.php
index 3342bce8d58..ed4107bd26d 100644
--- a/lib/Doctrine/DBAL/Exception/DatabaseObjectNotFoundException.php
+++ b/lib/Doctrine/DBAL/Exception/DatabaseObjectNotFoundException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/DeadlockException.php b/lib/Doctrine/DBAL/Exception/DeadlockException.php
index fd0550a56b0..5d71a3da95d 100644
--- a/lib/Doctrine/DBAL/Exception/DeadlockException.php
+++ b/lib/Doctrine/DBAL/Exception/DeadlockException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/DriverException.php b/lib/Doctrine/DBAL/Exception/DriverException.php
index d3753329882..831ddd08116 100644
--- a/lib/Doctrine/DBAL/Exception/DriverException.php
+++ b/lib/Doctrine/DBAL/Exception/DriverException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Exception/ForeignKeyConstraintViolationException.php b/lib/Doctrine/DBAL/Exception/ForeignKeyConstraintViolationException.php
index 48d736f9e28..166f8503bf9 100644
--- a/lib/Doctrine/DBAL/Exception/ForeignKeyConstraintViolationException.php
+++ b/lib/Doctrine/DBAL/Exception/ForeignKeyConstraintViolationException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/InvalidArgumentException.php b/lib/Doctrine/DBAL/Exception/InvalidArgumentException.php
index 5d431e6031d..b0fd74d3591 100644
--- a/lib/Doctrine/DBAL/Exception/InvalidArgumentException.php
+++ b/lib/Doctrine/DBAL/Exception/InvalidArgumentException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Exception/InvalidFieldNameException.php b/lib/Doctrine/DBAL/Exception/InvalidFieldNameException.php
index d960feaf869..316414b3e11 100644
--- a/lib/Doctrine/DBAL/Exception/InvalidFieldNameException.php
+++ b/lib/Doctrine/DBAL/Exception/InvalidFieldNameException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/LockWaitTimeoutException.php b/lib/Doctrine/DBAL/Exception/LockWaitTimeoutException.php
index bfc3a498a3c..4800de5cd7c 100644
--- a/lib/Doctrine/DBAL/Exception/LockWaitTimeoutException.php
+++ b/lib/Doctrine/DBAL/Exception/LockWaitTimeoutException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/NonUniqueFieldNameException.php b/lib/Doctrine/DBAL/Exception/NonUniqueFieldNameException.php
index fd56f89691f..ec2b0baac33 100644
--- a/lib/Doctrine/DBAL/Exception/NonUniqueFieldNameException.php
+++ b/lib/Doctrine/DBAL/Exception/NonUniqueFieldNameException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/NotNullConstraintViolationException.php b/lib/Doctrine/DBAL/Exception/NotNullConstraintViolationException.php
index e327bc94d4d..970be78f0ca 100644
--- a/lib/Doctrine/DBAL/Exception/NotNullConstraintViolationException.php
+++ b/lib/Doctrine/DBAL/Exception/NotNullConstraintViolationException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/ReadOnlyException.php b/lib/Doctrine/DBAL/Exception/ReadOnlyException.php
index a846f2501c8..6def0ac98cb 100644
--- a/lib/Doctrine/DBAL/Exception/ReadOnlyException.php
+++ b/lib/Doctrine/DBAL/Exception/ReadOnlyException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/RetryableException.php b/lib/Doctrine/DBAL/Exception/RetryableException.php
index e1ccd02ffd9..df44635f479 100644
--- a/lib/Doctrine/DBAL/Exception/RetryableException.php
+++ b/lib/Doctrine/DBAL/Exception/RetryableException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/ServerException.php b/lib/Doctrine/DBAL/Exception/ServerException.php
index c88c3863b62..ace7c234fdf 100644
--- a/lib/Doctrine/DBAL/Exception/ServerException.php
+++ b/lib/Doctrine/DBAL/Exception/ServerException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/SyntaxErrorException.php b/lib/Doctrine/DBAL/Exception/SyntaxErrorException.php
index 0b413b71971..893a4ceb49f 100644
--- a/lib/Doctrine/DBAL/Exception/SyntaxErrorException.php
+++ b/lib/Doctrine/DBAL/Exception/SyntaxErrorException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/TableExistsException.php b/lib/Doctrine/DBAL/Exception/TableExistsException.php
index ff0df89afac..bc8ea6e9e20 100644
--- a/lib/Doctrine/DBAL/Exception/TableExistsException.php
+++ b/lib/Doctrine/DBAL/Exception/TableExistsException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/TableNotFoundException.php b/lib/Doctrine/DBAL/Exception/TableNotFoundException.php
index aeaa0057d49..4fe86396942 100644
--- a/lib/Doctrine/DBAL/Exception/TableNotFoundException.php
+++ b/lib/Doctrine/DBAL/Exception/TableNotFoundException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/Exception/UniqueConstraintViolationException.php b/lib/Doctrine/DBAL/Exception/UniqueConstraintViolationException.php
index c762ad3c78a..0d51a721a54 100644
--- a/lib/Doctrine/DBAL/Exception/UniqueConstraintViolationException.php
+++ b/lib/Doctrine/DBAL/Exception/UniqueConstraintViolationException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Exception;
 
 /**
diff --git a/lib/Doctrine/DBAL/FetchMode.php b/lib/Doctrine/DBAL/FetchMode.php
index 65af014f1e0..ad0d22e6738 100644
--- a/lib/Doctrine/DBAL/FetchMode.php
+++ b/lib/Doctrine/DBAL/FetchMode.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 /**
diff --git a/lib/Doctrine/DBAL/Id/TableGenerator.php b/lib/Doctrine/DBAL/Id/TableGenerator.php
index cb34dcd5c4b..ad4770598e4 100644
--- a/lib/Doctrine/DBAL/Id/TableGenerator.php
+++ b/lib/Doctrine/DBAL/Id/TableGenerator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Id;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Id/TableGeneratorSchemaVisitor.php b/lib/Doctrine/DBAL/Id/TableGeneratorSchemaVisitor.php
index 3ec22f37c5c..9e2efa91b46 100644
--- a/lib/Doctrine/DBAL/Id/TableGeneratorSchemaVisitor.php
+++ b/lib/Doctrine/DBAL/Id/TableGeneratorSchemaVisitor.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Id;
 
 use Doctrine\DBAL\Schema\Column;
diff --git a/lib/Doctrine/DBAL/LockMode.php b/lib/Doctrine/DBAL/LockMode.php
index 14e81432b43..9c2f901d87c 100644
--- a/lib/Doctrine/DBAL/LockMode.php
+++ b/lib/Doctrine/DBAL/LockMode.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 /**
diff --git a/lib/Doctrine/DBAL/Logging/DebugStack.php b/lib/Doctrine/DBAL/Logging/DebugStack.php
index bd1358f321d..2cd85a8e35f 100644
--- a/lib/Doctrine/DBAL/Logging/DebugStack.php
+++ b/lib/Doctrine/DBAL/Logging/DebugStack.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Logging;
 
 use function microtime;
diff --git a/lib/Doctrine/DBAL/Logging/EchoSQLLogger.php b/lib/Doctrine/DBAL/Logging/EchoSQLLogger.php
index cfca9dd7c90..754b34269d7 100644
--- a/lib/Doctrine/DBAL/Logging/EchoSQLLogger.php
+++ b/lib/Doctrine/DBAL/Logging/EchoSQLLogger.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Logging;
 
 use const PHP_EOL;
diff --git a/lib/Doctrine/DBAL/Logging/LoggerChain.php b/lib/Doctrine/DBAL/Logging/LoggerChain.php
index 598f51e2a6b..e8ce945cf2b 100644
--- a/lib/Doctrine/DBAL/Logging/LoggerChain.php
+++ b/lib/Doctrine/DBAL/Logging/LoggerChain.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Logging;
 
 /**
diff --git a/lib/Doctrine/DBAL/Logging/NullLogger.php b/lib/Doctrine/DBAL/Logging/NullLogger.php
index b0ffb53c817..6269b6f610c 100644
--- a/lib/Doctrine/DBAL/Logging/NullLogger.php
+++ b/lib/Doctrine/DBAL/Logging/NullLogger.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Logging;
 
 /**
diff --git a/lib/Doctrine/DBAL/Logging/SQLLogger.php b/lib/Doctrine/DBAL/Logging/SQLLogger.php
index 99aa494426b..10d5b35823c 100644
--- a/lib/Doctrine/DBAL/Logging/SQLLogger.php
+++ b/lib/Doctrine/DBAL/Logging/SQLLogger.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Logging;
 
 /**
diff --git a/lib/Doctrine/DBAL/ParameterType.php b/lib/Doctrine/DBAL/ParameterType.php
index 022b2703ef5..b392ddbe95a 100644
--- a/lib/Doctrine/DBAL/ParameterType.php
+++ b/lib/Doctrine/DBAL/ParameterType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/AbstractPlatform.php b/lib/Doctrine/DBAL/Platforms/AbstractPlatform.php
index 07cdaa7a4d9..6d3bbee764e 100644
--- a/lib/Doctrine/DBAL/Platforms/AbstractPlatform.php
+++ b/lib/Doctrine/DBAL/Platforms/AbstractPlatform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\Common\EventManager;
diff --git a/lib/Doctrine/DBAL/Platforms/DB2Platform.php b/lib/Doctrine/DBAL/Platforms/DB2Platform.php
index f625b081905..b0ff5ab15ce 100644
--- a/lib/Doctrine/DBAL/Platforms/DB2Platform.php
+++ b/lib/Doctrine/DBAL/Platforms/DB2Platform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/DB2Keywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/DB2Keywords.php
index db577d30207..1327ffbeee2 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/DB2Keywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/DB2Keywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/KeywordList.php b/lib/Doctrine/DBAL/Platforms/Keywords/KeywordList.php
index 860d9f21099..251722313ff 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/KeywordList.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/KeywordList.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 use function array_flip;
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/MariaDb102Keywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/MariaDb102Keywords.php
index 1b31c7682e7..010f694232a 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/MariaDb102Keywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/MariaDb102Keywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/MySQL57Keywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/MySQL57Keywords.php
index 9b60a3f1c54..eda315f58cd 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/MySQL57Keywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/MySQL57Keywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/MySQL80Keywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/MySQL80Keywords.php
index 4b595d53a08..566a55552a6 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/MySQL80Keywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/MySQL80Keywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 use function array_merge;
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/MySQLKeywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/MySQLKeywords.php
index 84ca1446a8b..9ec94c2df61 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/MySQLKeywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/MySQLKeywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/OracleKeywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/OracleKeywords.php
index a73a93d60c0..c134693a6ba 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/OracleKeywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/OracleKeywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/PostgreSQL94Keywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/PostgreSQL94Keywords.php
index 7bf29cd2aa5..421819544f3 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/PostgreSQL94Keywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/PostgreSQL94Keywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 use function array_diff;
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/PostgreSQLKeywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/PostgreSQLKeywords.php
index 92b45609cc0..017b4e02f63 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/PostgreSQLKeywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/PostgreSQLKeywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/ReservedKeywordsValidator.php b/lib/Doctrine/DBAL/Platforms/Keywords/ReservedKeywordsValidator.php
index 68cdf3d15d8..4aab336d10e 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/ReservedKeywordsValidator.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/ReservedKeywordsValidator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 use Doctrine\DBAL\Schema\Column;
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/SQLAnywhereKeywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/SQLAnywhereKeywords.php
index dc60610738b..f7b6b0bd2a5 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/SQLAnywhereKeywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/SQLAnywhereKeywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/SQLServer2012Keywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/SQLServer2012Keywords.php
index d29225270aa..df64901862a 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/SQLServer2012Keywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/SQLServer2012Keywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 use function array_merge;
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/SQLServerKeywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/SQLServerKeywords.php
index e43bde2fe5c..b72e7342e3b 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/SQLServerKeywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/SQLServerKeywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/Keywords/SQLiteKeywords.php b/lib/Doctrine/DBAL/Platforms/Keywords/SQLiteKeywords.php
index a0c9c797ef9..22c92d72f11 100644
--- a/lib/Doctrine/DBAL/Platforms/Keywords/SQLiteKeywords.php
+++ b/lib/Doctrine/DBAL/Platforms/Keywords/SQLiteKeywords.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms\Keywords;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/MariaDb1027Platform.php b/lib/Doctrine/DBAL/Platforms/MariaDb1027Platform.php
index 6c57082c586..7390061721a 100644
--- a/lib/Doctrine/DBAL/Platforms/MariaDb1027Platform.php
+++ b/lib/Doctrine/DBAL/Platforms/MariaDb1027Platform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\Types\Types;
diff --git a/lib/Doctrine/DBAL/Platforms/MySQL57Platform.php b/lib/Doctrine/DBAL/Platforms/MySQL57Platform.php
index 1db7d6689b7..27118c71988 100644
--- a/lib/Doctrine/DBAL/Platforms/MySQL57Platform.php
+++ b/lib/Doctrine/DBAL/Platforms/MySQL57Platform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\Schema\Index;
diff --git a/lib/Doctrine/DBAL/Platforms/MySQL80Platform.php b/lib/Doctrine/DBAL/Platforms/MySQL80Platform.php
index f6d4be9dc4c..7e07dc9dbb7 100644
--- a/lib/Doctrine/DBAL/Platforms/MySQL80Platform.php
+++ b/lib/Doctrine/DBAL/Platforms/MySQL80Platform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 /**
diff --git a/lib/Doctrine/DBAL/Platforms/MySqlPlatform.php b/lib/Doctrine/DBAL/Platforms/MySqlPlatform.php
index 78e318df264..d8fb568bf1b 100644
--- a/lib/Doctrine/DBAL/Platforms/MySqlPlatform.php
+++ b/lib/Doctrine/DBAL/Platforms/MySqlPlatform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\Schema\ForeignKeyConstraint;
diff --git a/lib/Doctrine/DBAL/Platforms/OraclePlatform.php b/lib/Doctrine/DBAL/Platforms/OraclePlatform.php
index c463f722e5e..63f7442786c 100644
--- a/lib/Doctrine/DBAL/Platforms/OraclePlatform.php
+++ b/lib/Doctrine/DBAL/Platforms/OraclePlatform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Platforms/PostgreSQL94Platform.php b/lib/Doctrine/DBAL/Platforms/PostgreSQL94Platform.php
index ae90e8ff4d4..87d903b7feb 100644
--- a/lib/Doctrine/DBAL/Platforms/PostgreSQL94Platform.php
+++ b/lib/Doctrine/DBAL/Platforms/PostgreSQL94Platform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\Types\Types;
diff --git a/lib/Doctrine/DBAL/Platforms/PostgreSqlPlatform.php b/lib/Doctrine/DBAL/Platforms/PostgreSqlPlatform.php
index 3b5d46648e6..4fa61fbdeca 100644
--- a/lib/Doctrine/DBAL/Platforms/PostgreSqlPlatform.php
+++ b/lib/Doctrine/DBAL/Platforms/PostgreSqlPlatform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\Schema\Column;
@@ -901,7 +903,7 @@ static function ($boolean) {
      */
     public function convertFromBoolean($item)
     {
-        if (in_array(strtolower($item), $this->booleanLiterals['false'], true)) {
+        if (in_array($item, $this->booleanLiterals['false'], true)) {
             return false;
         }
 
diff --git a/lib/Doctrine/DBAL/Platforms/SQLAnywherePlatform.php b/lib/Doctrine/DBAL/Platforms/SQLAnywherePlatform.php
index 36714143b85..691d72ea908 100644
--- a/lib/Doctrine/DBAL/Platforms/SQLAnywherePlatform.php
+++ b/lib/Doctrine/DBAL/Platforms/SQLAnywherePlatform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Platforms/SQLAzurePlatform.php b/lib/Doctrine/DBAL/Platforms/SQLAzurePlatform.php
index c95d93c9a86..72e2acfa31b 100644
--- a/lib/Doctrine/DBAL/Platforms/SQLAzurePlatform.php
+++ b/lib/Doctrine/DBAL/Platforms/SQLAzurePlatform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\Schema\Table;
diff --git a/lib/Doctrine/DBAL/Platforms/SQLServer2012Platform.php b/lib/Doctrine/DBAL/Platforms/SQLServer2012Platform.php
index afc6a32b060..8066a772ae5 100644
--- a/lib/Doctrine/DBAL/Platforms/SQLServer2012Platform.php
+++ b/lib/Doctrine/DBAL/Platforms/SQLServer2012Platform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\Schema\Sequence;
diff --git a/lib/Doctrine/DBAL/Platforms/SQLServerPlatform.php b/lib/Doctrine/DBAL/Platforms/SQLServerPlatform.php
index 2ce1a784cd5..ad9e4e9f42d 100644
--- a/lib/Doctrine/DBAL/Platforms/SQLServerPlatform.php
+++ b/lib/Doctrine/DBAL/Platforms/SQLServerPlatform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\LockMode;
diff --git a/lib/Doctrine/DBAL/Platforms/SqlitePlatform.php b/lib/Doctrine/DBAL/Platforms/SqlitePlatform.php
index f2842f8e16a..a8630569e6d 100644
--- a/lib/Doctrine/DBAL/Platforms/SqlitePlatform.php
+++ b/lib/Doctrine/DBAL/Platforms/SqlitePlatform.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Platforms;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Portability/Connection.php b/lib/Doctrine/DBAL/Portability/Connection.php
index 5194b66a611..8c64822f9e0 100644
--- a/lib/Doctrine/DBAL/Portability/Connection.php
+++ b/lib/Doctrine/DBAL/Portability/Connection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Portability;
 
 use Doctrine\DBAL\Cache\QueryCacheProfile;
diff --git a/lib/Doctrine/DBAL/Portability/Statement.php b/lib/Doctrine/DBAL/Portability/Statement.php
index 7e9edfeadb3..c2ab9534fd7 100644
--- a/lib/Doctrine/DBAL/Portability/Statement.php
+++ b/lib/Doctrine/DBAL/Portability/Statement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Portability;
 
 use Doctrine\DBAL\Driver\ResultStatement;
diff --git a/lib/Doctrine/DBAL/Query/Expression/CompositeExpression.php b/lib/Doctrine/DBAL/Query/Expression/CompositeExpression.php
index 443d71bc37e..93600f0ffb4 100644
--- a/lib/Doctrine/DBAL/Query/Expression/CompositeExpression.php
+++ b/lib/Doctrine/DBAL/Query/Expression/CompositeExpression.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Query\Expression;
 
 use Countable;
diff --git a/lib/Doctrine/DBAL/Query/Expression/ExpressionBuilder.php b/lib/Doctrine/DBAL/Query/Expression/ExpressionBuilder.php
index 93cbd31e95f..573df7b60b0 100644
--- a/lib/Doctrine/DBAL/Query/Expression/ExpressionBuilder.php
+++ b/lib/Doctrine/DBAL/Query/Expression/ExpressionBuilder.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Query\Expression;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Query/QueryBuilder.php b/lib/Doctrine/DBAL/Query/QueryBuilder.php
index 5c18d6edd4f..f3e92a2ad6f 100644
--- a/lib/Doctrine/DBAL/Query/QueryBuilder.php
+++ b/lib/Doctrine/DBAL/Query/QueryBuilder.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Query;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Query/QueryException.php b/lib/Doctrine/DBAL/Query/QueryException.php
index 3fcb3b480ec..b692557051d 100644
--- a/lib/Doctrine/DBAL/Query/QueryException.php
+++ b/lib/Doctrine/DBAL/Query/QueryException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Query;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/SQLParserUtils.php b/lib/Doctrine/DBAL/SQLParserUtils.php
index 9768883846e..66ca8f6e025 100644
--- a/lib/Doctrine/DBAL/SQLParserUtils.php
+++ b/lib/Doctrine/DBAL/SQLParserUtils.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 use const PREG_OFFSET_CAPTURE;
diff --git a/lib/Doctrine/DBAL/SQLParserUtilsException.php b/lib/Doctrine/DBAL/SQLParserUtilsException.php
index a500ed52dd3..e2d8bbac65d 100644
--- a/lib/Doctrine/DBAL/SQLParserUtilsException.php
+++ b/lib/Doctrine/DBAL/SQLParserUtilsException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 use function sprintf;
diff --git a/lib/Doctrine/DBAL/Schema/AbstractAsset.php b/lib/Doctrine/DBAL/Schema/AbstractAsset.php
index 45af02f5cc9..cfa469d9de7 100644
--- a/lib/Doctrine/DBAL/Schema/AbstractAsset.php
+++ b/lib/Doctrine/DBAL/Schema/AbstractAsset.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
@@ -166,7 +168,7 @@ public function getName()
             return $this->_namespace . '.' . $this->_name;
         }
 
-        return $this->_name;
+        return $this->_name ?? '';
     }
 
     /**
diff --git a/lib/Doctrine/DBAL/Schema/AbstractSchemaManager.php b/lib/Doctrine/DBAL/Schema/AbstractSchemaManager.php
index 46fbff6da30..a3edcdb2206 100644
--- a/lib/Doctrine/DBAL/Schema/AbstractSchemaManager.php
+++ b/lib/Doctrine/DBAL/Schema/AbstractSchemaManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Schema/Column.php b/lib/Doctrine/DBAL/Schema/Column.php
index 56c39c14994..5c21b708aaa 100644
--- a/lib/Doctrine/DBAL/Schema/Column.php
+++ b/lib/Doctrine/DBAL/Schema/Column.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Types\Type;
diff --git a/lib/Doctrine/DBAL/Schema/ColumnDiff.php b/lib/Doctrine/DBAL/Schema/ColumnDiff.php
index 1589f98d4a9..f98f9108bfd 100644
--- a/lib/Doctrine/DBAL/Schema/ColumnDiff.php
+++ b/lib/Doctrine/DBAL/Schema/ColumnDiff.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use function in_array;
diff --git a/lib/Doctrine/DBAL/Schema/Comparator.php b/lib/Doctrine/DBAL/Schema/Comparator.php
index 9ccaa9a1efa..f7712ec2da4 100644
--- a/lib/Doctrine/DBAL/Schema/Comparator.php
+++ b/lib/Doctrine/DBAL/Schema/Comparator.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Types;
diff --git a/lib/Doctrine/DBAL/Schema/Constraint.php b/lib/Doctrine/DBAL/Schema/Constraint.php
index 65e239ec119..c939a06e33e 100644
--- a/lib/Doctrine/DBAL/Schema/Constraint.php
+++ b/lib/Doctrine/DBAL/Schema/Constraint.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Schema/DB2SchemaManager.php b/lib/Doctrine/DBAL/Schema/DB2SchemaManager.php
index 0a056d3deff..0b0bd96a1c9 100644
--- a/lib/Doctrine/DBAL/Schema/DB2SchemaManager.php
+++ b/lib/Doctrine/DBAL/Schema/DB2SchemaManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Types\Type;
diff --git a/lib/Doctrine/DBAL/Schema/ForeignKeyConstraint.php b/lib/Doctrine/DBAL/Schema/ForeignKeyConstraint.php
index 3c6585e4600..3ccd2ede590 100644
--- a/lib/Doctrine/DBAL/Schema/ForeignKeyConstraint.php
+++ b/lib/Doctrine/DBAL/Schema/ForeignKeyConstraint.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
@@ -90,7 +92,7 @@ private function createIdentifierMap(array $names) : array
         $identifiers = [];
 
         foreach ($names as $name) {
-            $identifiers[$name] = new Identifier($name);
+            $identifiers[$name] = new Identifier($name ?? '');
         }
 
         return $identifiers;
diff --git a/lib/Doctrine/DBAL/Schema/Identifier.php b/lib/Doctrine/DBAL/Schema/Identifier.php
index f34465e9efb..276b7824f1a 100644
--- a/lib/Doctrine/DBAL/Schema/Identifier.php
+++ b/lib/Doctrine/DBAL/Schema/Identifier.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 /**
diff --git a/lib/Doctrine/DBAL/Schema/Index.php b/lib/Doctrine/DBAL/Schema/Index.php
index 18a26b8d306..b895f3e14a8 100644
--- a/lib/Doctrine/DBAL/Schema/Index.php
+++ b/lib/Doctrine/DBAL/Schema/Index.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
@@ -57,7 +59,9 @@ public function __construct($indexName, array $columns, $isUnique = false, $isPr
     {
         $isUnique = $isUnique || $isPrimary;
 
-        $this->_setName($indexName);
+        if ($indexName !== null) {
+            $this->_setName($indexName);
+        }
 
         $this->_isUnique  = $isUnique;
         $this->_isPrimary = $isPrimary;
diff --git a/lib/Doctrine/DBAL/Schema/MySqlSchemaManager.php b/lib/Doctrine/DBAL/Schema/MySqlSchemaManager.php
index 3af0f2c1eda..ff95f095f10 100644
--- a/lib/Doctrine/DBAL/Schema/MySqlSchemaManager.php
+++ b/lib/Doctrine/DBAL/Schema/MySqlSchemaManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\MariaDb1027Platform;
diff --git a/lib/Doctrine/DBAL/Schema/OracleSchemaManager.php b/lib/Doctrine/DBAL/Schema/OracleSchemaManager.php
index c7ecbf17b26..a0b6c709f2a 100644
--- a/lib/Doctrine/DBAL/Schema/OracleSchemaManager.php
+++ b/lib/Doctrine/DBAL/Schema/OracleSchemaManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\DBALException;
@@ -99,7 +101,7 @@ protected function _getPortableTableIndexesList(array $tableIndexRows, string $t
             $keyName = strtolower($tableIndex['name']);
             $buffer  = [];
 
-            if (strtolower($tableIndex['is_primary']) === 'p') {
+            if ($tableIndex['is_primary'] === 'P') {
                 $keyName              = 'primary';
                 $buffer['primary']    = true;
                 $buffer['non_unique'] = false;
@@ -138,7 +140,9 @@ protected function _getPortableTableColumnDefinition($tableColumn)
         }
 
         // Default values returned from database sometimes have trailing spaces.
-        $tableColumn['data_default'] = trim($tableColumn['data_default']);
+        if ($tableColumn['data_default'] !== null) {
+            $tableColumn['data_default'] = trim($tableColumn['data_default']);
+        }
 
         if ($tableColumn['data_default'] === '' || $tableColumn['data_default'] === 'NULL') {
             $tableColumn['data_default'] = null;
diff --git a/lib/Doctrine/DBAL/Schema/PostgreSqlSchemaManager.php b/lib/Doctrine/DBAL/Schema/PostgreSqlSchemaManager.php
index 77fa286cfc4..84bd56ec960 100644
--- a/lib/Doctrine/DBAL/Schema/PostgreSqlSchemaManager.php
+++ b/lib/Doctrine/DBAL/Schema/PostgreSqlSchemaManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Exception\DriverException;
@@ -323,16 +325,18 @@ protected function _getPortableTableColumnDefinition($tableColumn)
         $matches = [];
 
         $autoincrement = false;
-        if (preg_match("/^nextval\('(.*)'(::.*)?\)$/", $tableColumn['default'], $matches)) {
+        if ($tableColumn['default'] !== null && preg_match("/^nextval\('(.*)'(::.*)?\)$/", $tableColumn['default'], $matches)) {
             $tableColumn['sequence'] = $matches[1];
             $tableColumn['default']  = null;
             $autoincrement           = true;
         }
 
-        if (preg_match("/^['(](.*)[')]::/", $tableColumn['default'], $matches)) {
-            $tableColumn['default'] = $matches[1];
-        } elseif (preg_match('/^NULL::/', $tableColumn['default'])) {
-            $tableColumn['default'] = null;
+        if ($tableColumn['default'] !== null) {
+            if (preg_match("/^['(](.*)[')]::/", $tableColumn['default'], $matches)) {
+                $tableColumn['default'] = $matches[1];
+            } elseif (preg_match('/^NULL::/', $tableColumn['default'])) {
+                $tableColumn['default'] = null;
+            }
         }
 
         $length = $tableColumn['length'] ?? null;
@@ -353,7 +357,10 @@ protected function _getPortableTableColumnDefinition($tableColumn)
         $jsonb     = null;
 
         $dbType = strtolower($tableColumn['type']);
-        if (strlen($tableColumn['domain_type']) && ! $this->_platform->hasDoctrineTypeMappingFor($tableColumn['type'])) {
+        if ($tableColumn['domain_type'] !== null
+            && strlen($tableColumn['domain_type'])
+            && ! $this->_platform->hasDoctrineTypeMappingFor($tableColumn['type'])
+        ) {
             $dbType                       = strtolower($tableColumn['domain_type']);
             $tableColumn['complete_type'] = $tableColumn['domain_complete_type'];
         }
@@ -471,7 +478,7 @@ protected function _getPortableTableColumnDefinition($tableColumn)
      */
     private function fixVersion94NegativeNumericDefaultValue($defaultValue)
     {
-        if (strpos($defaultValue, '(') === 0) {
+        if ($defaultValue !== null && strpos($defaultValue, '(') === 0) {
             return trim($defaultValue, '()');
         }
 
diff --git a/lib/Doctrine/DBAL/Schema/SQLAnywhereSchemaManager.php b/lib/Doctrine/DBAL/Schema/SQLAnywhereSchemaManager.php
index 0d875491167..b99d68429e0 100644
--- a/lib/Doctrine/DBAL/Schema/SQLAnywhereSchemaManager.php
+++ b/lib/Doctrine/DBAL/Schema/SQLAnywhereSchemaManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\SQLAnywherePlatform;
diff --git a/lib/Doctrine/DBAL/Schema/SQLServerSchemaManager.php b/lib/Doctrine/DBAL/Schema/SQLServerSchemaManager.php
index 6de597a4257..7872ee3f3e5 100644
--- a/lib/Doctrine/DBAL/Schema/SQLServerSchemaManager.php
+++ b/lib/Doctrine/DBAL/Schema/SQLServerSchemaManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Schema/Schema.php b/lib/Doctrine/DBAL/Schema/Schema.php
index 5d746654a40..fa7e2472e15 100644
--- a/lib/Doctrine/DBAL/Schema/Schema.php
+++ b/lib/Doctrine/DBAL/Schema/Schema.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Schema/SchemaConfig.php b/lib/Doctrine/DBAL/Schema/SchemaConfig.php
index b8c3502f758..e3a2f36b0b4 100644
--- a/lib/Doctrine/DBAL/Schema/SchemaConfig.php
+++ b/lib/Doctrine/DBAL/Schema/SchemaConfig.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 /**
diff --git a/lib/Doctrine/DBAL/Schema/SchemaDiff.php b/lib/Doctrine/DBAL/Schema/SchemaDiff.php
index 69bf125a844..97033eeeebb 100644
--- a/lib/Doctrine/DBAL/Schema/SchemaDiff.php
+++ b/lib/Doctrine/DBAL/Schema/SchemaDiff.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Schema/SchemaException.php b/lib/Doctrine/DBAL/Schema/SchemaException.php
index 658663ac16a..1271e9db0a6 100644
--- a/lib/Doctrine/DBAL/Schema/SchemaException.php
+++ b/lib/Doctrine/DBAL/Schema/SchemaException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Schema/Sequence.php b/lib/Doctrine/DBAL/Schema/Sequence.php
index 88891019bfd..89147984136 100644
--- a/lib/Doctrine/DBAL/Schema/Sequence.php
+++ b/lib/Doctrine/DBAL/Schema/Sequence.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Schema\Visitor\Visitor;
diff --git a/lib/Doctrine/DBAL/Schema/SqliteSchemaManager.php b/lib/Doctrine/DBAL/Schema/SqliteSchemaManager.php
index 2556fa29764..d71e3e57c8a 100644
--- a/lib/Doctrine/DBAL/Schema/SqliteSchemaManager.php
+++ b/lib/Doctrine/DBAL/Schema/SqliteSchemaManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Schema/Synchronizer/AbstractSchemaSynchronizer.php b/lib/Doctrine/DBAL/Schema/Synchronizer/AbstractSchemaSynchronizer.php
index b597b8db9b2..74dce854098 100644
--- a/lib/Doctrine/DBAL/Schema/Synchronizer/AbstractSchemaSynchronizer.php
+++ b/lib/Doctrine/DBAL/Schema/Synchronizer/AbstractSchemaSynchronizer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Synchronizer;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Schema/Synchronizer/SchemaSynchronizer.php b/lib/Doctrine/DBAL/Schema/Synchronizer/SchemaSynchronizer.php
index 3e7beea7508..8e0eb117c4f 100644
--- a/lib/Doctrine/DBAL/Schema/Synchronizer/SchemaSynchronizer.php
+++ b/lib/Doctrine/DBAL/Schema/Synchronizer/SchemaSynchronizer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Synchronizer;
 
 use Doctrine\DBAL\Schema\Schema;
diff --git a/lib/Doctrine/DBAL/Schema/Synchronizer/SingleDatabaseSynchronizer.php b/lib/Doctrine/DBAL/Schema/Synchronizer/SingleDatabaseSynchronizer.php
index dd4b1ca5f40..83abc250596 100644
--- a/lib/Doctrine/DBAL/Schema/Synchronizer/SingleDatabaseSynchronizer.php
+++ b/lib/Doctrine/DBAL/Schema/Synchronizer/SingleDatabaseSynchronizer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Synchronizer;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Schema/Table.php b/lib/Doctrine/DBAL/Schema/Table.php
index 781df0ed27a..855f2a457e9 100644
--- a/lib/Doctrine/DBAL/Schema/Table.php
+++ b/lib/Doctrine/DBAL/Schema/Table.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Schema/TableDiff.php b/lib/Doctrine/DBAL/Schema/TableDiff.php
index 1ff2c0ad105..bdbce7da3b3 100644
--- a/lib/Doctrine/DBAL/Schema/TableDiff.php
+++ b/lib/Doctrine/DBAL/Schema/TableDiff.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Schema/UniqueConstraint.php b/lib/Doctrine/DBAL/Schema/UniqueConstraint.php
index 8d47424769c..44f0f5cd150 100644
--- a/lib/Doctrine/DBAL/Schema/UniqueConstraint.php
+++ b/lib/Doctrine/DBAL/Schema/UniqueConstraint.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Schema/View.php b/lib/Doctrine/DBAL/Schema/View.php
index ac8d6cb5cb4..18ca8664c9e 100644
--- a/lib/Doctrine/DBAL/Schema/View.php
+++ b/lib/Doctrine/DBAL/Schema/View.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema;
 
 /**
diff --git a/lib/Doctrine/DBAL/Schema/Visitor/AbstractVisitor.php b/lib/Doctrine/DBAL/Schema/Visitor/AbstractVisitor.php
index 47169044274..318ba1f1126 100644
--- a/lib/Doctrine/DBAL/Schema/Visitor/AbstractVisitor.php
+++ b/lib/Doctrine/DBAL/Schema/Visitor/AbstractVisitor.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Schema\Column;
diff --git a/lib/Doctrine/DBAL/Schema/Visitor/CreateSchemaSqlCollector.php b/lib/Doctrine/DBAL/Schema/Visitor/CreateSchemaSqlCollector.php
index cc15bc0f655..cea93eeb4f1 100644
--- a/lib/Doctrine/DBAL/Schema/Visitor/CreateSchemaSqlCollector.php
+++ b/lib/Doctrine/DBAL/Schema/Visitor/CreateSchemaSqlCollector.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Schema/Visitor/DropSchemaSqlCollector.php b/lib/Doctrine/DBAL/Schema/Visitor/DropSchemaSqlCollector.php
index 81e2023128b..6e6b1e62f2e 100644
--- a/lib/Doctrine/DBAL/Schema/Visitor/DropSchemaSqlCollector.php
+++ b/lib/Doctrine/DBAL/Schema/Visitor/DropSchemaSqlCollector.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Schema/Visitor/Graphviz.php b/lib/Doctrine/DBAL/Schema/Visitor/Graphviz.php
index 06e8413c8a4..96aa180133a 100644
--- a/lib/Doctrine/DBAL/Schema/Visitor/Graphviz.php
+++ b/lib/Doctrine/DBAL/Schema/Visitor/Graphviz.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Schema\ForeignKeyConstraint;
diff --git a/lib/Doctrine/DBAL/Schema/Visitor/NamespaceVisitor.php b/lib/Doctrine/DBAL/Schema/Visitor/NamespaceVisitor.php
index 186fe1b4213..fd09ff7cdab 100644
--- a/lib/Doctrine/DBAL/Schema/Visitor/NamespaceVisitor.php
+++ b/lib/Doctrine/DBAL/Schema/Visitor/NamespaceVisitor.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Visitor;
 
 /**
diff --git a/lib/Doctrine/DBAL/Schema/Visitor/RemoveNamespacedAssets.php b/lib/Doctrine/DBAL/Schema/Visitor/RemoveNamespacedAssets.php
index 001ea2a0d70..196e43e46c3 100644
--- a/lib/Doctrine/DBAL/Schema/Visitor/RemoveNamespacedAssets.php
+++ b/lib/Doctrine/DBAL/Schema/Visitor/RemoveNamespacedAssets.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Schema\ForeignKeyConstraint;
diff --git a/lib/Doctrine/DBAL/Schema/Visitor/SchemaDiffVisitor.php b/lib/Doctrine/DBAL/Schema/Visitor/SchemaDiffVisitor.php
index 5ec843d9be6..358ddf7d777 100644
--- a/lib/Doctrine/DBAL/Schema/Visitor/SchemaDiffVisitor.php
+++ b/lib/Doctrine/DBAL/Schema/Visitor/SchemaDiffVisitor.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Schema\ForeignKeyConstraint;
diff --git a/lib/Doctrine/DBAL/Schema/Visitor/Visitor.php b/lib/Doctrine/DBAL/Schema/Visitor/Visitor.php
index 05c842830c5..3d80991c4d9 100644
--- a/lib/Doctrine/DBAL/Schema/Visitor/Visitor.php
+++ b/lib/Doctrine/DBAL/Schema/Visitor/Visitor.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Schema\Column;
diff --git a/lib/Doctrine/DBAL/Sharding/PoolingShardConnection.php b/lib/Doctrine/DBAL/Sharding/PoolingShardConnection.php
index 649a4e256fe..99e015b176e 100644
--- a/lib/Doctrine/DBAL/Sharding/PoolingShardConnection.php
+++ b/lib/Doctrine/DBAL/Sharding/PoolingShardConnection.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Sharding;
 
 use Doctrine\Common\EventManager;
diff --git a/lib/Doctrine/DBAL/Sharding/PoolingShardManager.php b/lib/Doctrine/DBAL/Sharding/PoolingShardManager.php
index 5edc56b8778..d0efce31ab2 100644
--- a/lib/Doctrine/DBAL/Sharding/PoolingShardManager.php
+++ b/lib/Doctrine/DBAL/Sharding/PoolingShardManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Sharding;
 
 use Doctrine\DBAL\Sharding\ShardChoser\ShardChoser;
diff --git a/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureFederationsSynchronizer.php b/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureFederationsSynchronizer.php
index 417f674a3e0..d7501b27897 100644
--- a/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureFederationsSynchronizer.php
+++ b/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureFederationsSynchronizer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Sharding\SQLAzure;
 
 use Closure;
diff --git a/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureShardManager.php b/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureShardManager.php
index 11bd965c158..40fb9db3bd6 100644
--- a/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureShardManager.php
+++ b/lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureShardManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Sharding\SQLAzure;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Sharding/SQLAzure/Schema/MultiTenantVisitor.php b/lib/Doctrine/DBAL/Sharding/SQLAzure/Schema/MultiTenantVisitor.php
index a83b401c2cd..dd35e119a57 100644
--- a/lib/Doctrine/DBAL/Sharding/SQLAzure/Schema/MultiTenantVisitor.php
+++ b/lib/Doctrine/DBAL/Sharding/SQLAzure/Schema/MultiTenantVisitor.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Sharding\SQLAzure\Schema;
 
 use Doctrine\DBAL\Schema\Column;
diff --git a/lib/Doctrine/DBAL/Sharding/ShardChoser/MultiTenantShardChoser.php b/lib/Doctrine/DBAL/Sharding/ShardChoser/MultiTenantShardChoser.php
index 584e8155ae9..c6c2f3843f4 100644
--- a/lib/Doctrine/DBAL/Sharding/ShardChoser/MultiTenantShardChoser.php
+++ b/lib/Doctrine/DBAL/Sharding/ShardChoser/MultiTenantShardChoser.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Sharding\ShardChoser;
 
 use Doctrine\DBAL\Sharding\PoolingShardConnection;
diff --git a/lib/Doctrine/DBAL/Sharding/ShardChoser/ShardChoser.php b/lib/Doctrine/DBAL/Sharding/ShardChoser/ShardChoser.php
index 6f8a9d47702..57c247aa65b 100644
--- a/lib/Doctrine/DBAL/Sharding/ShardChoser/ShardChoser.php
+++ b/lib/Doctrine/DBAL/Sharding/ShardChoser/ShardChoser.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Sharding\ShardChoser;
 
 use Doctrine\DBAL\Sharding\PoolingShardConnection;
diff --git a/lib/Doctrine/DBAL/Sharding/ShardManager.php b/lib/Doctrine/DBAL/Sharding/ShardManager.php
index 7b37bb2c7e1..793b0bb9340 100644
--- a/lib/Doctrine/DBAL/Sharding/ShardManager.php
+++ b/lib/Doctrine/DBAL/Sharding/ShardManager.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Sharding;
 
 /**
diff --git a/lib/Doctrine/DBAL/Sharding/ShardingException.php b/lib/Doctrine/DBAL/Sharding/ShardingException.php
index b46bda2ff0d..3e6c91c3844 100644
--- a/lib/Doctrine/DBAL/Sharding/ShardingException.php
+++ b/lib/Doctrine/DBAL/Sharding/ShardingException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Sharding;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Statement.php b/lib/Doctrine/DBAL/Statement.php
index fc6608fb3d2..7022c809b61 100644
--- a/lib/Doctrine/DBAL/Statement.php
+++ b/lib/Doctrine/DBAL/Statement.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 use Doctrine\DBAL\Driver\DriverException;
diff --git a/lib/Doctrine/DBAL/Tools/Console/Command/ReservedWordsCommand.php b/lib/Doctrine/DBAL/Tools/Console/Command/ReservedWordsCommand.php
index a8020a15399..020e9b2164f 100644
--- a/lib/Doctrine/DBAL/Tools/Console/Command/ReservedWordsCommand.php
+++ b/lib/Doctrine/DBAL/Tools/Console/Command/ReservedWordsCommand.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Tools\Console\Command;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Tools/Console/Command/RunSqlCommand.php b/lib/Doctrine/DBAL/Tools/Console/Command/RunSqlCommand.php
index 8aeb0ea2fba..2a55fb6df36 100644
--- a/lib/Doctrine/DBAL/Tools/Console/Command/RunSqlCommand.php
+++ b/lib/Doctrine/DBAL/Tools/Console/Command/RunSqlCommand.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Tools\Console\Command;
 
 use Doctrine\DBAL\Tools\Dumper;
diff --git a/lib/Doctrine/DBAL/Tools/Console/ConsoleRunner.php b/lib/Doctrine/DBAL/Tools/Console/ConsoleRunner.php
index 0df6f086f2c..32a00549c77 100644
--- a/lib/Doctrine/DBAL/Tools/Console/ConsoleRunner.php
+++ b/lib/Doctrine/DBAL/Tools/Console/ConsoleRunner.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Tools\Console;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Tools/Console/Helper/ConnectionHelper.php b/lib/Doctrine/DBAL/Tools/Console/Helper/ConnectionHelper.php
index b5497d068a0..836bd8d8568 100644
--- a/lib/Doctrine/DBAL/Tools/Console/Helper/ConnectionHelper.php
+++ b/lib/Doctrine/DBAL/Tools/Console/Helper/ConnectionHelper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Tools\Console\Helper;
 
 use Doctrine\DBAL\Connection;
diff --git a/lib/Doctrine/DBAL/Tools/Dumper.php b/lib/Doctrine/DBAL/Tools/Dumper.php
index 3668efbe4d1..36f44555414 100644
--- a/lib/Doctrine/DBAL/Tools/Dumper.php
+++ b/lib/Doctrine/DBAL/Tools/Dumper.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Tools;
 
 use ArrayIterator;
@@ -58,11 +60,11 @@ public static function dump($var, int $maxDepth = 2) : string
         $html = ini_get('html_errors');
 
         if ($html !== true) {
-            ini_set('html_errors', true);
+            ini_set('html_errors', '1');
         }
 
         if (extension_loaded('xdebug')) {
-            ini_set('xdebug.var_display_max_depth', $maxDepth);
+            ini_set('xdebug.var_display_max_depth', (string) $maxDepth);
         }
 
         $var = self::export($var, $maxDepth);
@@ -149,7 +151,7 @@ private static function fillReturnWithClassAttributes($var, stdClass $return, in
         $clone = (array) $var;
 
         foreach (array_keys($clone) as $key) {
-            $aux  = explode("\0", $key);
+            $aux  = explode("\0", (string) $key);
             $name = end($aux);
             if ($aux[0] === '') {
                 $name .= ':' . ($aux[1] === '*' ? 'protected' : $aux[1] . ':private');
diff --git a/lib/Doctrine/DBAL/Types/ArrayType.php b/lib/Doctrine/DBAL/Types/ArrayType.php
index e981ded1eca..8b4f2e7d044 100644
--- a/lib/Doctrine/DBAL/Types/ArrayType.php
+++ b/lib/Doctrine/DBAL/Types/ArrayType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Types/BigIntType.php b/lib/Doctrine/DBAL/Types/BigIntType.php
index 69cd5341d84..2b42e66f9e2 100644
--- a/lib/Doctrine/DBAL/Types/BigIntType.php
+++ b/lib/Doctrine/DBAL/Types/BigIntType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\ParameterType;
diff --git a/lib/Doctrine/DBAL/Types/BinaryType.php b/lib/Doctrine/DBAL/Types/BinaryType.php
index 8aefd610401..b4a50d104af 100644
--- a/lib/Doctrine/DBAL/Types/BinaryType.php
+++ b/lib/Doctrine/DBAL/Types/BinaryType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\ParameterType;
diff --git a/lib/Doctrine/DBAL/Types/BlobType.php b/lib/Doctrine/DBAL/Types/BlobType.php
index e4bb22f08d8..cfb5c292897 100644
--- a/lib/Doctrine/DBAL/Types/BlobType.php
+++ b/lib/Doctrine/DBAL/Types/BlobType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\ParameterType;
diff --git a/lib/Doctrine/DBAL/Types/BooleanType.php b/lib/Doctrine/DBAL/Types/BooleanType.php
index bf9be9b19fe..47da8044622 100644
--- a/lib/Doctrine/DBAL/Types/BooleanType.php
+++ b/lib/Doctrine/DBAL/Types/BooleanType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\ParameterType;
diff --git a/lib/Doctrine/DBAL/Types/ConversionException.php b/lib/Doctrine/DBAL/Types/ConversionException.php
index b9f8a82e7ec..325c8c2d3f8 100644
--- a/lib/Doctrine/DBAL/Types/ConversionException.php
+++ b/lib/Doctrine/DBAL/Types/ConversionException.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\DBALException;
@@ -9,6 +11,7 @@
 use function implode;
 use function is_object;
 use function is_scalar;
+use function is_string;
 use function sprintf;
 use function strlen;
 use function substr;
@@ -21,14 +24,14 @@ class ConversionException extends DBALException
     /**
      * Thrown when a Database to Doctrine Type Conversion fails.
      *
-     * @param string $value
+     * @param mixed  $value
      * @param string $toType
      *
      * @return \Doctrine\DBAL\Types\ConversionException
      */
     public static function conversionFailed($value, $toType)
     {
-        $value = strlen($value) > 32 ? substr($value, 0, 20) . '...' : $value;
+        $value = is_string($value) && strlen($value) > 32 ? substr($value, 0, 20) . '...' : $value;
 
         return new self('Could not convert database value "' . $value . '" to Doctrine Type ' . $toType);
     }
@@ -37,7 +40,7 @@ public static function conversionFailed($value, $toType)
      * Thrown when a Database to Doctrine Type Conversion fails and we can make a statement
      * about the expected format.
      *
-     * @param string $value
+     * @param mixed  $value
      * @param string $toType
      * @param string $expectedFormat
      *
@@ -45,7 +48,7 @@ public static function conversionFailed($value, $toType)
      */
     public static function conversionFailedFormat($value, $toType, $expectedFormat, ?Throwable $previous = null)
     {
-        $value = strlen($value) > 32 ? substr($value, 0, 20) . '...' : $value;
+        $value = is_string($value) && strlen($value) > 32 ? substr($value, 0, 20) . '...' : $value;
 
         return new self(
             'Could not convert database value "' . $value . '" to Doctrine Type ' .
diff --git a/lib/Doctrine/DBAL/Types/DateImmutableType.php b/lib/Doctrine/DBAL/Types/DateImmutableType.php
index a4c5d266d92..e824513a5b7 100644
--- a/lib/Doctrine/DBAL/Types/DateImmutableType.php
+++ b/lib/Doctrine/DBAL/Types/DateImmutableType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateTimeImmutable;
diff --git a/lib/Doctrine/DBAL/Types/DateIntervalType.php b/lib/Doctrine/DBAL/Types/DateIntervalType.php
index 96a446e8607..af9cb25ce2c 100644
--- a/lib/Doctrine/DBAL/Types/DateIntervalType.php
+++ b/lib/Doctrine/DBAL/Types/DateIntervalType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateInterval;
diff --git a/lib/Doctrine/DBAL/Types/DateTimeImmutableType.php b/lib/Doctrine/DBAL/Types/DateTimeImmutableType.php
index 51960a8c344..4ed1a32cf77 100644
--- a/lib/Doctrine/DBAL/Types/DateTimeImmutableType.php
+++ b/lib/Doctrine/DBAL/Types/DateTimeImmutableType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateTimeImmutable;
diff --git a/lib/Doctrine/DBAL/Types/DateTimeType.php b/lib/Doctrine/DBAL/Types/DateTimeType.php
index 65071a6b188..4d0d26095ff 100644
--- a/lib/Doctrine/DBAL/Types/DateTimeType.php
+++ b/lib/Doctrine/DBAL/Types/DateTimeType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateTime;
diff --git a/lib/Doctrine/DBAL/Types/DateTimeTzImmutableType.php b/lib/Doctrine/DBAL/Types/DateTimeTzImmutableType.php
index b888624796e..7320faf7e73 100644
--- a/lib/Doctrine/DBAL/Types/DateTimeTzImmutableType.php
+++ b/lib/Doctrine/DBAL/Types/DateTimeTzImmutableType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateTimeImmutable;
diff --git a/lib/Doctrine/DBAL/Types/DateTimeTzType.php b/lib/Doctrine/DBAL/Types/DateTimeTzType.php
index 6240da8926c..5f0785cb878 100644
--- a/lib/Doctrine/DBAL/Types/DateTimeTzType.php
+++ b/lib/Doctrine/DBAL/Types/DateTimeTzType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateTime;
diff --git a/lib/Doctrine/DBAL/Types/DateType.php b/lib/Doctrine/DBAL/Types/DateType.php
index 15d9362f288..b449fc9540f 100644
--- a/lib/Doctrine/DBAL/Types/DateType.php
+++ b/lib/Doctrine/DBAL/Types/DateType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateTime;
diff --git a/lib/Doctrine/DBAL/Types/DecimalType.php b/lib/Doctrine/DBAL/Types/DecimalType.php
index b2d37f00b3e..78a0cc6662c 100644
--- a/lib/Doctrine/DBAL/Types/DecimalType.php
+++ b/lib/Doctrine/DBAL/Types/DecimalType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Types/FloatType.php b/lib/Doctrine/DBAL/Types/FloatType.php
index 4988d7253dc..17553756e10 100644
--- a/lib/Doctrine/DBAL/Types/FloatType.php
+++ b/lib/Doctrine/DBAL/Types/FloatType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Types/GuidType.php b/lib/Doctrine/DBAL/Types/GuidType.php
index dd4516505ec..add076e115b 100644
--- a/lib/Doctrine/DBAL/Types/GuidType.php
+++ b/lib/Doctrine/DBAL/Types/GuidType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Types/IntegerType.php b/lib/Doctrine/DBAL/Types/IntegerType.php
index d7ab8fd80f2..4d6bad1e12c 100644
--- a/lib/Doctrine/DBAL/Types/IntegerType.php
+++ b/lib/Doctrine/DBAL/Types/IntegerType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\ParameterType;
diff --git a/lib/Doctrine/DBAL/Types/JsonArrayType.php b/lib/Doctrine/DBAL/Types/JsonArrayType.php
index bc468fba0f3..999433d0c79 100644
--- a/lib/Doctrine/DBAL/Types/JsonArrayType.php
+++ b/lib/Doctrine/DBAL/Types/JsonArrayType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Types/JsonType.php b/lib/Doctrine/DBAL/Types/JsonType.php
index 127f3fa8ee1..d4731129bf9 100644
--- a/lib/Doctrine/DBAL/Types/JsonType.php
+++ b/lib/Doctrine/DBAL/Types/JsonType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Types/ObjectType.php b/lib/Doctrine/DBAL/Types/ObjectType.php
index 32f5f4efd02..3af15fe8f39 100644
--- a/lib/Doctrine/DBAL/Types/ObjectType.php
+++ b/lib/Doctrine/DBAL/Types/ObjectType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Types/PhpDateTimeMappingType.php b/lib/Doctrine/DBAL/Types/PhpDateTimeMappingType.php
index 45658505330..501bc37a7be 100644
--- a/lib/Doctrine/DBAL/Types/PhpDateTimeMappingType.php
+++ b/lib/Doctrine/DBAL/Types/PhpDateTimeMappingType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 /**
diff --git a/lib/Doctrine/DBAL/Types/PhpIntegerMappingType.php b/lib/Doctrine/DBAL/Types/PhpIntegerMappingType.php
index b48e29c865a..d2b208478d1 100644
--- a/lib/Doctrine/DBAL/Types/PhpIntegerMappingType.php
+++ b/lib/Doctrine/DBAL/Types/PhpIntegerMappingType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 /**
diff --git a/lib/Doctrine/DBAL/Types/SimpleArrayType.php b/lib/Doctrine/DBAL/Types/SimpleArrayType.php
index 31c22b8e6f6..69f3900a56e 100644
--- a/lib/Doctrine/DBAL/Types/SimpleArrayType.php
+++ b/lib/Doctrine/DBAL/Types/SimpleArrayType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Types/SmallIntType.php b/lib/Doctrine/DBAL/Types/SmallIntType.php
index 5fa3cb74bbc..bd99b26247e 100644
--- a/lib/Doctrine/DBAL/Types/SmallIntType.php
+++ b/lib/Doctrine/DBAL/Types/SmallIntType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\ParameterType;
diff --git a/lib/Doctrine/DBAL/Types/StringType.php b/lib/Doctrine/DBAL/Types/StringType.php
index 8a4d7e28a39..c9473a4a325 100644
--- a/lib/Doctrine/DBAL/Types/StringType.php
+++ b/lib/Doctrine/DBAL/Types/StringType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Types/TextType.php b/lib/Doctrine/DBAL/Types/TextType.php
index 76dd7c48cf0..1e8236ad36c 100644
--- a/lib/Doctrine/DBAL/Types/TextType.php
+++ b/lib/Doctrine/DBAL/Types/TextType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/lib/Doctrine/DBAL/Types/TimeImmutableType.php b/lib/Doctrine/DBAL/Types/TimeImmutableType.php
index cc437695564..96cc5a35652 100644
--- a/lib/Doctrine/DBAL/Types/TimeImmutableType.php
+++ b/lib/Doctrine/DBAL/Types/TimeImmutableType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateTimeImmutable;
diff --git a/lib/Doctrine/DBAL/Types/TimeType.php b/lib/Doctrine/DBAL/Types/TimeType.php
index 1eeb2c01d1f..b1df33440f5 100644
--- a/lib/Doctrine/DBAL/Types/TimeType.php
+++ b/lib/Doctrine/DBAL/Types/TimeType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateTime;
diff --git a/lib/Doctrine/DBAL/Types/Type.php b/lib/Doctrine/DBAL/Types/Type.php
index f9e1bfbe595..87f74b3a958 100644
--- a/lib/Doctrine/DBAL/Types/Type.php
+++ b/lib/Doctrine/DBAL/Types/Type.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use Doctrine\DBAL\DBALException;
diff --git a/lib/Doctrine/DBAL/Types/VarDateTimeImmutableType.php b/lib/Doctrine/DBAL/Types/VarDateTimeImmutableType.php
index 38beb3badf6..d74dfe48721 100644
--- a/lib/Doctrine/DBAL/Types/VarDateTimeImmutableType.php
+++ b/lib/Doctrine/DBAL/Types/VarDateTimeImmutableType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateTimeImmutable;
diff --git a/lib/Doctrine/DBAL/Types/VarDateTimeType.php b/lib/Doctrine/DBAL/Types/VarDateTimeType.php
index 1d9dbd3a6c6..fe431da91e8 100644
--- a/lib/Doctrine/DBAL/Types/VarDateTimeType.php
+++ b/lib/Doctrine/DBAL/Types/VarDateTimeType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL\Types;
 
 use DateTime;
diff --git a/lib/Doctrine/DBAL/VersionAwarePlatformDriver.php b/lib/Doctrine/DBAL/VersionAwarePlatformDriver.php
index a4864d0b287..c61f47d2df0 100644
--- a/lib/Doctrine/DBAL/VersionAwarePlatformDriver.php
+++ b/lib/Doctrine/DBAL/VersionAwarePlatformDriver.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\DBAL;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/phpcs.xml.dist b/phpcs.xml.dist
index 6c4117a7c52..9c1b6e36343 100644
--- a/phpcs.xml.dist
+++ b/phpcs.xml.dist
@@ -14,7 +14,6 @@
     <file>tests</file>
 
     <rule ref="Doctrine">
-        <exclude name="SlevomatCodingStandard.TypeHints.DeclareStrictTypes"/>
         <exclude name="SlevomatCodingStandard.Classes.SuperfluousAbstractClassNaming"/>
         <exclude name="SlevomatCodingStandard.Classes.SuperfluousExceptionNaming"/>
         <exclude name="SlevomatCodingStandard.ControlStructures.ControlStructureSpacing.IncorrectLinesCountAfterLastControlStructure"/>
@@ -72,4 +71,10 @@
     <rule ref="SlevomatCodingStandard.Operators.DisallowEqualOperators.DisallowedNotEqualOperator">
         <exclude-pattern>lib/Doctrine/DBAL/Schema/Comparator.php</exclude-pattern>
     </rule>
+
+    <!-- DB2_AUTOCOMMIT_ON/DB2_AUTOCOMMIT_OFF are of int type but db2_autocommit() incorrectly expects bool,
+         see https://bugs.php.net/bug.php?id=77591 -->
+    <rule ref="SlevomatCodingStandard.TypeHints.DeclareStrictTypes.DeclareStrictTypesMissing">
+        <exclude-pattern>lib/Doctrine/DBAL/Driver/IBMDB2/DB2Connection.php</exclude-pattern>
+    </rule>
 </ruleset>
diff --git a/tests/Doctrine/Tests/DBAL/Cache/QueryCacheProfileTest.php b/tests/Doctrine/Tests/DBAL/Cache/QueryCacheProfileTest.php
index 217b27d1f2f..2deb312b382 100644
--- a/tests/Doctrine/Tests/DBAL/Cache/QueryCacheProfileTest.php
+++ b/tests/Doctrine/Tests/DBAL/Cache/QueryCacheProfileTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Cache;
 
 use Doctrine\DBAL\Cache\QueryCacheProfile;
diff --git a/tests/Doctrine/Tests/DBAL/ConfigurationTest.php b/tests/Doctrine/Tests/DBAL/ConfigurationTest.php
index 6b478e82b5e..6eba08b88f8 100644
--- a/tests/Doctrine/Tests/DBAL/ConfigurationTest.php
+++ b/tests/Doctrine/Tests/DBAL/ConfigurationTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL;
 
 use Doctrine\DBAL\Configuration;
diff --git a/tests/Doctrine/Tests/DBAL/ConnectionTest.php b/tests/Doctrine/Tests/DBAL/ConnectionTest.php
index 6d6ff75c11a..8e1b84cdd1b 100644
--- a/tests/Doctrine/Tests/DBAL/ConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/ConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL;
 
 use Doctrine\Common\Cache\Cache;
diff --git a/tests/Doctrine/Tests/DBAL/DBALExceptionTest.php b/tests/Doctrine/Tests/DBAL/DBALExceptionTest.php
index 7db5921ba79..115d40ccd91 100644
--- a/tests/Doctrine/Tests/DBAL/DBALExceptionTest.php
+++ b/tests/Doctrine/Tests/DBAL/DBALExceptionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL;
 
 use Doctrine\DBAL\DBALException;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/AbstractDB2DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/AbstractDB2DriverTest.php
index 7038f5f8340..e9750ad9adf 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/AbstractDB2DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/AbstractDB2DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/AbstractDriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/AbstractDriverTest.php
index d2a5422a179..1a42cf00f98 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/AbstractDriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/AbstractDriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/AbstractMySQLDriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/AbstractMySQLDriverTest.php
index 4982a189e05..793b5d9aa42 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/AbstractMySQLDriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/AbstractMySQLDriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/AbstractOracleDriver/EasyConnectStringTest.php b/tests/Doctrine/Tests/DBAL/Driver/AbstractOracleDriver/EasyConnectStringTest.php
index efb250d1ac7..e53b7ae695f 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/AbstractOracleDriver/EasyConnectStringTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/AbstractOracleDriver/EasyConnectStringTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\AbstractOracleDriver;
 
 use Doctrine\DBAL\Driver\AbstractOracleDriver\EasyConnectString;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/AbstractOracleDriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/AbstractOracleDriverTest.php
index f95705a8a88..10a5fdb01bd 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/AbstractOracleDriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/AbstractOracleDriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/AbstractPostgreSQLDriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/AbstractPostgreSQLDriverTest.php
index 9f1daca35cd..df0b2c936a1 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/AbstractPostgreSQLDriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/AbstractPostgreSQLDriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLAnywhereDriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLAnywhereDriverTest.php
index e025ef82cd1..dd551e69f59 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLAnywhereDriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLAnywhereDriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLServerDriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLServerDriverTest.php
index 330b4b5e4d8..4e650548d57 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLServerDriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLServerDriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLiteDriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLiteDriverTest.php
index 338f9126077..8486250e960 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLiteDriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/AbstractSQLiteDriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/IBMDB2/DB2ConnectionTest.php b/tests/Doctrine/Tests/DBAL/Driver/IBMDB2/DB2ConnectionTest.php
index cf2db940b33..db4270d5652 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/IBMDB2/DB2ConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/IBMDB2/DB2ConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\IBMDB2;
 
 use Doctrine\DBAL\Driver\IBMDB2\DB2Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/IBMDB2/DB2DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/IBMDB2/DB2DriverTest.php
index dcf9f6083e3..359919bcb21 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/IBMDB2/DB2DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/IBMDB2/DB2DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\IBMDB2;
 
 use Doctrine\DBAL\Driver as DriverInterface;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/Mysqli/DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/Mysqli/DriverTest.php
index bbe16b34717..d9cd63e55ee 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/Mysqli/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/Mysqli/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\Mysqli;
 
 use Doctrine\DBAL\Driver as DriverInterface;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/Mysqli/MysqliConnectionTest.php b/tests/Doctrine/Tests/DBAL/Driver/Mysqli/MysqliConnectionTest.php
index 07af588023c..15bb4e50fe3 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/Mysqli/MysqliConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/Mysqli/MysqliConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\Mysqli;
 
 use Doctrine\DBAL\Driver\Mysqli\MysqliConnection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/OCI8/DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/OCI8/DriverTest.php
index 7b6ed1d5a55..8cf945a06a7 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/OCI8/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/OCI8/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\OCI8;
 
 use Doctrine\DBAL\Driver as DriverInterface;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/OCI8/OCI8ConnectionTest.php b/tests/Doctrine/Tests/DBAL/Driver/OCI8/OCI8ConnectionTest.php
index 4c3868f4a95..0c54cc88c6c 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/OCI8/OCI8ConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/OCI8/OCI8ConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\OCI8;
 
 use Doctrine\DBAL\Driver\OCI8\OCI8Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/OCI8/OCI8StatementTest.php b/tests/Doctrine/Tests/DBAL/Driver/OCI8/OCI8StatementTest.php
index 645af64695e..300cbd9e77e 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/OCI8/OCI8StatementTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/OCI8/OCI8StatementTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\OCI8;
 
 use Doctrine\DBAL\Driver\OCI8\OCI8Connection;
@@ -7,7 +9,9 @@
 use Doctrine\DBAL\Driver\OCI8\OCI8Statement;
 use Doctrine\Tests\DbalTestCase;
 use ReflectionProperty;
+use const OCI_NO_AUTO_COMMIT;
 use function extension_loaded;
+use function fopen;
 
 class OCI8StatementTest extends DbalTestCase
 {
@@ -57,11 +61,16 @@ public function testExecute(array $params) : void
             ->disableOriginalConstructor()
             ->getMock();
         $conn->expects($this->once())
-            ->method('getExecuteMode');
+            ->method('getExecuteMode')
+            ->willReturn(OCI_NO_AUTO_COMMIT);
+
+        $connectionReflection = new ReflectionProperty($statement, '_conn');
+        $connectionReflection->setAccessible(true);
+        $connectionReflection->setValue($statement, $conn);
 
-        $reflProperty = new ReflectionProperty($statement, '_conn');
-        $reflProperty->setAccessible(true);
-        $reflProperty->setValue($statement, $conn);
+        $handleReflection = new ReflectionProperty($statement, '_sth');
+        $handleReflection->setAccessible(true);
+        $handleReflection->setValue($statement, fopen('php://temp', 'r'));
 
         $this->expectException(OCI8Exception::class);
         $statement->execute($params);
diff --git a/tests/Doctrine/Tests/DBAL/Driver/PDOExceptionTest.php b/tests/Doctrine/Tests/DBAL/Driver/PDOExceptionTest.php
index 9ed9a06aa5b..4c97602ce9d 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/PDOExceptionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/PDOExceptionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver;
 
 use Doctrine\DBAL\Driver\PDOException;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/PDOMySql/DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/PDOMySql/DriverTest.php
index 6e3ef7d5a03..69a82515925 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/PDOMySql/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/PDOMySql/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\PDOMySql;
 
 use Doctrine\DBAL\Driver as DriverInterface;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/PDOOracle/DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/PDOOracle/DriverTest.php
index 42353be376d..909cde556ea 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/PDOOracle/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/PDOOracle/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\PDOOracle;
 
 use Doctrine\DBAL\Driver as DriverInterface;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/PDOPgSql/DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/PDOPgSql/DriverTest.php
index ba0036ebe4a..b105524cc36 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/PDOPgSql/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/PDOPgSql/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\PDOPgSql;
 
 use Doctrine\DBAL\Driver as DriverInterface;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/PDOSqlite/DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/PDOSqlite/DriverTest.php
index 9092b091e3a..645499018ff 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/PDOSqlite/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/PDOSqlite/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\PDOSqlite;
 
 use Doctrine\DBAL\Driver as DriverInterface;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/PDOSqlsrv/DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/PDOSqlsrv/DriverTest.php
index c92dc86d5ba..de632c436b3 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/PDOSqlsrv/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/PDOSqlsrv/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\PDOSqlsrv;
 
 use Doctrine\DBAL\Driver as DriverInterface;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/SQLAnywhere/DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/SQLAnywhere/DriverTest.php
index d6f1595a45e..2669715f41d 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/SQLAnywhere/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/SQLAnywhere/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\SQLAnywhere;
 
 use Doctrine\DBAL\Driver as DriverInterface;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/SQLAnywhere/SQLAnywhereConnectionTest.php b/tests/Doctrine/Tests/DBAL/Driver/SQLAnywhere/SQLAnywhereConnectionTest.php
index effeb483362..d78a95fa6da 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/SQLAnywhere/SQLAnywhereConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/SQLAnywhere/SQLAnywhereConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\SQLAnywhere;
 
 use Doctrine\DBAL\Driver\SQLAnywhere\SQLAnywhereConnection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/SQLSrv/DriverTest.php b/tests/Doctrine/Tests/DBAL/Driver/SQLSrv/DriverTest.php
index 9ab6635ecf4..eb96db4e839 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/SQLSrv/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/SQLSrv/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\SQLSrv;
 
 use Doctrine\DBAL\Driver as DriverInterface;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/SQLSrv/SQLSrvConnectionTest.php b/tests/Doctrine/Tests/DBAL/Driver/SQLSrv/SQLSrvConnectionTest.php
index 8d457d8eb23..4225e65c2dd 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/SQLSrv/SQLSrvConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/SQLSrv/SQLSrvConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver\SQLSrv;
 
 use Doctrine\DBAL\Driver\SQLSrv\SQLSrvConnection;
diff --git a/tests/Doctrine/Tests/DBAL/Driver/StatementIteratorTest.php b/tests/Doctrine/Tests/DBAL/Driver/StatementIteratorTest.php
index 90244cd2ac8..63cc84c41d3 100644
--- a/tests/Doctrine/Tests/DBAL/Driver/StatementIteratorTest.php
+++ b/tests/Doctrine/Tests/DBAL/Driver/StatementIteratorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Driver;
 
 use Doctrine\DBAL\Driver\IBMDB2\DB2Statement;
diff --git a/tests/Doctrine/Tests/DBAL/DriverManagerTest.php b/tests/Doctrine/Tests/DBAL/DriverManagerTest.php
index 5b93d0fca7d..f44b9f5bf6b 100644
--- a/tests/Doctrine/Tests/DBAL/DriverManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/DriverManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Events/MysqlSessionInitTest.php b/tests/Doctrine/Tests/DBAL/Events/MysqlSessionInitTest.php
index daea3a754c6..d8e8a256862 100644
--- a/tests/Doctrine/Tests/DBAL/Events/MysqlSessionInitTest.php
+++ b/tests/Doctrine/Tests/DBAL/Events/MysqlSessionInitTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Events;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Events/OracleSessionInitTest.php b/tests/Doctrine/Tests/DBAL/Events/OracleSessionInitTest.php
index 998b1dc916e..88fbc34a00f 100644
--- a/tests/Doctrine/Tests/DBAL/Events/OracleSessionInitTest.php
+++ b/tests/Doctrine/Tests/DBAL/Events/OracleSessionInitTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Events;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Events/SQLSessionInitTest.php b/tests/Doctrine/Tests/DBAL/Events/SQLSessionInitTest.php
index c69b2996827..b8014983793 100644
--- a/tests/Doctrine/Tests/DBAL/Events/SQLSessionInitTest.php
+++ b/tests/Doctrine/Tests/DBAL/Events/SQLSessionInitTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Events;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Exception/InvalidArgumentExceptionTest.php b/tests/Doctrine/Tests/DBAL/Exception/InvalidArgumentExceptionTest.php
index 7718a6bc9d8..43bfbec47a8 100644
--- a/tests/Doctrine/Tests/DBAL/Exception/InvalidArgumentExceptionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Exception/InvalidArgumentExceptionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Exception;
 
 use Doctrine\DBAL\Exception\InvalidArgumentException;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/BlobTest.php b/tests/Doctrine/Tests/DBAL/Functional/BlobTest.php
index a12d0600201..c3a14419276 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/BlobTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/BlobTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\Driver\OCI8\Driver as OCI8Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/ConnectionTest.php b/tests/Doctrine/Tests/DBAL/Functional/ConnectionTest.php
index 0588aa15fc4..0bd89184aef 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/ConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/ConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/DataAccessTest.php b/tests/Doctrine/Tests/DBAL/Functional/DataAccessTest.php
index 39be5159b3e..2c4030e7608 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/DataAccessTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/DataAccessTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use DateTime;
@@ -926,8 +928,8 @@ public function testLocateExpression() : void
         $sql .= $platform->getLocateExpression("'foo'", 'test_string') . ' AS locate5, ';
         $sql .= $platform->getLocateExpression("'barfoobaz'", 'test_string') . ' AS locate6, ';
         $sql .= $platform->getLocateExpression("'bar'", 'test_string') . ' AS locate7, ';
-        $sql .= $platform->getLocateExpression('test_string', "'oo'", 2) . ' AS locate8, ';
-        $sql .= $platform->getLocateExpression('test_string', "'oo'", 3) . ' AS locate9 ';
+        $sql .= $platform->getLocateExpression('test_string', "'oo'", '2') . ' AS locate8, ';
+        $sql .= $platform->getLocateExpression('test_string', "'oo'", '3') . ' AS locate9 ';
         $sql .= 'FROM fetch_table';
 
         $row = $this->connection->fetchAssoc($sql);
@@ -1017,8 +1019,8 @@ public function testBitComparisonExpressionSupport() : void
         $sql[] = 'SELECT ';
         $sql[] = 'test_int, ';
         $sql[] = 'test_string, ';
-        $sql[] = $platform->getBitOrComparisonExpression('test_int', 2) . ' AS bit_or, ';
-        $sql[] = $platform->getBitAndComparisonExpression('test_int', 2) . ' AS bit_and ';
+        $sql[] = $platform->getBitOrComparisonExpression('test_int', '2') . ' AS bit_or, ';
+        $sql[] = $platform->getBitAndComparisonExpression('test_int', '2') . ' AS bit_and ';
         $sql[] = 'FROM fetch_table';
 
         $stmt = $this->connection->executeQuery(implode(PHP_EOL, $sql));
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/AbstractDriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/AbstractDriverTest.php
index 3adf3c2bb89..0669f8b6539 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/AbstractDriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/AbstractDriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/IBMDB2/DB2DriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/IBMDB2/DB2DriverTest.php
index 4021bb2fff7..4b5f3673613 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/IBMDB2/DB2DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/IBMDB2/DB2DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\IBMDB2;
 
 use Doctrine\DBAL\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/Mysqli/ConnectionTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/Mysqli/ConnectionTest.php
index 4a3a315f296..924305e25b3 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/Mysqli/ConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/Mysqli/ConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\Mysqli;
 
 use Doctrine\DBAL\Driver\Mysqli\Driver;
@@ -61,7 +63,7 @@ private function getConnection(array $driverOptions) : MysqliConnection
             [
                 'host' => $GLOBALS['db_host'],
                 'dbname' => $GLOBALS['db_name'],
-                'port' => $GLOBALS['db_port'],
+                'port' => (int) $GLOBALS['db_port'],
             ],
             $GLOBALS['db_username'],
             $GLOBALS['db_password'],
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/Mysqli/DriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/Mysqli/DriverTest.php
index d4bbf9a1df7..ea20af2ed59 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/Mysqli/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/Mysqli/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\Mysqli;
 
 use Doctrine\DBAL\Driver as DriverInterface;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/DriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/DriverTest.php
index 861ce650e76..9c89faedab4 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\OCI8;
 
 use Doctrine\DBAL\Driver as DriverInterface;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/OCI8ConnectionTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/OCI8ConnectionTest.php
index d6184316fac..4aaa091dbe5 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/OCI8ConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/OCI8ConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\OCI8;
 
 use Doctrine\DBAL\Driver\OCI8\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/StatementTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/StatementTest.php
index 8ecbed68082..0a26106a968 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/StatementTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/OCI8/StatementTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\OCI8;
 
 use Doctrine\DBAL\Driver\OCI8\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOConnectionTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOConnectionTest.php
index 204103a771a..15e97a0eef7 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver;
 
 use Doctrine\DBAL\Driver\PDOConnection;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOMySql/DriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOMySql/DriverTest.php
index 7f77ea542f9..44392eea5b4 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOMySql/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOMySql/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\PDOMySql;
 
 use Doctrine\DBAL\Driver as DriverInterface;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOOracle/DriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOOracle/DriverTest.php
index b096fa47e94..224adc34189 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOOracle/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOOracle/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\PDOOracle;
 
 use Doctrine\DBAL\Driver as DriverInterface;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOPgSql/DriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOPgSql/DriverTest.php
index b5f9d3eda9d..5a392031044 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOPgSql/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOPgSql/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\PDOPgSql;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOPgsqlConnectionTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOPgsqlConnectionTest.php
index 8336a3900d1..a7bdc75b81c 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOPgsqlConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOPgsqlConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver;
 
 use Doctrine\DBAL\DriverManager;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOSqlite/DriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOSqlite/DriverTest.php
index efc0382d85f..8d354ed5fb0 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOSqlite/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOSqlite/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\PDOSqlite;
 
 use Doctrine\DBAL\Driver as DriverInterface;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOSqlsrv/DriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOSqlsrv/DriverTest.php
index ef468ccb99c..3f738ef5a8e 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOSqlsrv/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/PDOSqlsrv/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\PDOSqlsrv;
 
 use Doctrine\DBAL\Driver as DriverInterface;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/ConnectionTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/ConnectionTest.php
index 4de7b7cde03..aaff05b11f2 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/ConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/ConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\SQLAnywhere;
 
 use Doctrine\DBAL\Driver\SQLAnywhere\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/DriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/DriverTest.php
index f2d54c62845..7ddb4b9c807 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\SQLAnywhere;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/StatementTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/StatementTest.php
index c09eb0a5d56..e781f7083f5 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/StatementTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLAnywhere/StatementTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\SQLAnywhere;
 
 use Doctrine\DBAL\Driver\SQLAnywhere\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLSrv/DriverTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLSrv/DriverTest.php
index eb9931a43dc..df8657525c5 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLSrv/DriverTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLSrv/DriverTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\SQLSrv;
 
 use Doctrine\DBAL\Driver as DriverInterface;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLSrv/StatementTest.php b/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLSrv/StatementTest.php
index 29df5aea958..53e39efe307 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLSrv/StatementTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Driver/SQLSrv/StatementTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Driver\SQLSrv;
 
 use Doctrine\DBAL\Driver\SQLSrv\Driver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/ExceptionTest.php b/tests/Doctrine/Tests/DBAL/Functional/ExceptionTest.php
index cb4a3f5d953..1f572a9a1d0 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/ExceptionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/ExceptionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\Driver\ExceptionConverterDriver;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/LikeWildcardsEscapingTest.php b/tests/Doctrine/Tests/DBAL/Functional/LikeWildcardsEscapingTest.php
index e172816f2af..a7c037bc951 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/LikeWildcardsEscapingTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/LikeWildcardsEscapingTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\Tests\DbalFunctionalTestCase;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/LoggingTest.php b/tests/Doctrine/Tests/DBAL/Functional/LoggingTest.php
index aa63af708df..9fbba19d759 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/LoggingTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/LoggingTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\Logging\SQLLogger;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/MasterSlaveConnectionTest.php b/tests/Doctrine/Tests/DBAL/Functional/MasterSlaveConnectionTest.php
index 2731ac995b8..fd53c14917b 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/MasterSlaveConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/MasterSlaveConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\Connections\MasterSlaveConnection;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/ModifyLimitQueryTest.php b/tests/Doctrine/Tests/DBAL/Functional/ModifyLimitQueryTest.php
index a14f9b17582..65bbd2cbe45 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/ModifyLimitQueryTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/ModifyLimitQueryTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\Schema\Table;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/NamedParametersTest.php b/tests/Doctrine/Tests/DBAL/Functional/NamedParametersTest.php
index 33e116ec368..5b11125fda7 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/NamedParametersTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/NamedParametersTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/PDOStatementTest.php b/tests/Doctrine/Tests/DBAL/Functional/PDOStatementTest.php
index 42b8104a9e7..6f9a2eda973 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/PDOStatementTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/PDOStatementTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\Driver\PDOConnection;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Platform/DateExpressionTest.php b/tests/Doctrine/Tests/DBAL/Functional/Platform/DateExpressionTest.php
index 5c1789e192d..b82cf0869c0 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Platform/DateExpressionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Platform/DateExpressionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Platform;
 
 use DateTimeImmutable;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Platform/NewPrimaryKeyWithNewAutoIncrementColumnTest.php b/tests/Doctrine/Tests/DBAL/Functional/Platform/NewPrimaryKeyWithNewAutoIncrementColumnTest.php
index 42e08f3f6d7..0fa5d3fec28 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Platform/NewPrimaryKeyWithNewAutoIncrementColumnTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Platform/NewPrimaryKeyWithNewAutoIncrementColumnTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Platform;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Platform/QuotingTest.php b/tests/Doctrine/Tests/DBAL/Functional/Platform/QuotingTest.php
index 3a1ae7c8440..542aca07318 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Platform/QuotingTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Platform/QuotingTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Platform;
 
 use Doctrine\Tests\DbalFunctionalTestCase;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/PortabilityTest.php b/tests/Doctrine/Tests/DBAL/Functional/PortabilityTest.php
index 72fb9dd2213..9ce3c90fff4 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/PortabilityTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/PortabilityTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\ColumnCase;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/ResultCacheTest.php b/tests/Doctrine/Tests/DBAL/Functional/ResultCacheTest.php
index 35ce061b5b9..4361ff503bc 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/ResultCacheTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/ResultCacheTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\Common\Cache\ArrayCache;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Schema/Db2SchemaManagerTest.php b/tests/Doctrine/Tests/DBAL/Functional/Schema/Db2SchemaManagerTest.php
index 330198e9ca9..28707b3b6a0 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Schema/Db2SchemaManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Schema/Db2SchemaManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Schema;
 
 use Doctrine\DBAL\Schema\Table;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Schema/MySqlSchemaManagerTest.php b/tests/Doctrine/Tests/DBAL/Functional/Schema/MySqlSchemaManagerTest.php
index e9a88e52096..93017676f31 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Schema/MySqlSchemaManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Schema/MySqlSchemaManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Schema;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Schema/OracleSchemaManagerTest.php b/tests/Doctrine/Tests/DBAL/Functional/Schema/OracleSchemaManagerTest.php
index b2363b639f0..01b76d2bcc9 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Schema/OracleSchemaManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Schema/OracleSchemaManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Schema;
 
 use Doctrine\DBAL\Schema;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Schema/PostgreSqlSchemaManagerTest.php b/tests/Doctrine/Tests/DBAL/Functional/Schema/PostgreSqlSchemaManagerTest.php
index 35326968798..c7080cb7a57 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Schema/PostgreSqlSchemaManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Schema/PostgreSqlSchemaManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
@@ -402,7 +404,7 @@ public function testJsonbColumn(string $type) : void
         $columns = $this->schemaManager->listTableColumns('test_jsonb');
 
         self::assertSame($type, $columns['foo']->getType()->getName());
-        self::assertTrue(true, $columns['foo']->getPlatformOption('jsonb'));
+        self::assertTrue($columns['foo']->getPlatformOption('jsonb'));
     }
 
     /**
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Schema/SQLAnywhereSchemaManagerTest.php b/tests/Doctrine/Tests/DBAL/Functional/Schema/SQLAnywhereSchemaManagerTest.php
index ffb5d6cf5ec..aa5fe608718 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Schema/SQLAnywhereSchemaManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Schema/SQLAnywhereSchemaManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Schema;
 
 use Doctrine\DBAL\Schema\Index;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Schema/SQLServerSchemaManagerTest.php b/tests/Doctrine/Tests/DBAL/Functional/Schema/SQLServerSchemaManagerTest.php
index f8b3b66c15c..186e860bddf 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Schema/SQLServerSchemaManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Schema/SQLServerSchemaManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Schema;
 
 use Doctrine\DBAL\Schema\Column;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Schema/SchemaManagerFunctionalTestCase.php b/tests/Doctrine/Tests/DBAL/Functional/Schema/SchemaManagerFunctionalTestCase.php
index d7278920b9a..3842774432b 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Schema/SchemaManagerFunctionalTestCase.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Schema/SchemaManagerFunctionalTestCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Schema;
 
 use Doctrine\Common\EventManager;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Schema/SqliteSchemaManagerTest.php b/tests/Doctrine/Tests/DBAL/Functional/Schema/SqliteSchemaManagerTest.php
index cce8f92f72d..f6ab16add9f 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Schema/SqliteSchemaManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Schema/SqliteSchemaManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Schema;
 
 use Doctrine\DBAL\DBALException;
@@ -98,7 +100,7 @@ public function testListForeignKeysFromExistingDatabase() : void
             new Schema\ForeignKeyConstraint(
                 ['log'],
                 'log',
-                [null],
+                [''],
                 'FK_3',
                 ['onUpdate' => 'SET NULL', 'onDelete' => 'NO ACTION', 'deferrable' => false, 'deferred' => false]
             ),
diff --git a/tests/Doctrine/Tests/DBAL/Functional/StatementTest.php b/tests/Doctrine/Tests/DBAL/Functional/StatementTest.php
index 98995bb5d02..22df34c59cb 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/StatementTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/StatementTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\DBALException;
@@ -367,7 +369,7 @@ public function testExecWithRedundantParameters() : void
 
         // we want to make sure the exception is thrown by the DBAL code, not by PHPUnit due to a PHP-level error,
         // but the wrapper connection wraps everything in a DBAL exception
-        $this->iniSet('error_reporting', 0);
+        $this->iniSet('error_reporting', '0');
 
         self::expectException(DBALException::class);
         $stmt->execute([null]);
diff --git a/tests/Doctrine/Tests/DBAL/Functional/TableGeneratorTest.php b/tests/Doctrine/Tests/DBAL/Functional/TableGeneratorTest.php
index 9846bf70fa1..34847c6295c 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/TableGeneratorTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/TableGeneratorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\Id\TableGenerator;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/TemporaryTableTest.php b/tests/Doctrine/Tests/DBAL/Functional/TemporaryTableTest.php
index e96fd426b3a..e0bc611ee27 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/TemporaryTableTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/TemporaryTableTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\Schema\Table;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL168Test.php b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL168Test.php
index a3133635c0d..e7c95b51737 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL168Test.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL168Test.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Ticket;
 
 use Doctrine\DBAL\Schema\Table;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL202Test.php b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL202Test.php
index da1fbcbd2f1..fd049e01901 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL202Test.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL202Test.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Ticket;
 
 use Doctrine\DBAL\Schema\Table;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL461Test.php b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL461Test.php
index e1c0927d852..9a0feb2e53a 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL461Test.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL461Test.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Ticket;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL510Test.php b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL510Test.php
index 1b3008db65d..989e1a77e21 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL510Test.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL510Test.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Ticket;
 
 use Doctrine\DBAL\Schema\Comparator;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL630Test.php b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL630Test.php
index b146d5a00fa..00d6face160 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL630Test.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL630Test.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Ticket;
 
 use Doctrine\DBAL\DBALException;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL752Test.php b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL752Test.php
index 47bc1c3e762..7f0a44e1795 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL752Test.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/Ticket/DBAL752Test.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional\Ticket;
 
 use Doctrine\Tests\DbalFunctionalTestCase;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/TransactionTest.php b/tests/Doctrine/Tests/DBAL/Functional/TransactionTest.php
index e846c973655..1fad213c6d0 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/TransactionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/TransactionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use Doctrine\DBAL\Driver\Mysqli\Exception\ConnectionError;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/TypeConversionTest.php b/tests/Doctrine/Tests/DBAL/Functional/TypeConversionTest.php
index 0d034edada2..6870cecfcd3 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/TypeConversionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/TypeConversionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Functional/WriteTest.php b/tests/Doctrine/Tests/DBAL/Functional/WriteTest.php
index 83705695425..52af49892f6 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/WriteTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/WriteTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Functional;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Logging/DebugStackTest.php b/tests/Doctrine/Tests/DBAL/Logging/DebugStackTest.php
index 3d4bfd2582c..497450e5e36 100644
--- a/tests/Doctrine/Tests/DBAL/Logging/DebugStackTest.php
+++ b/tests/Doctrine/Tests/DBAL/Logging/DebugStackTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Logging;
 
 use Doctrine\DBAL\Logging\DebugStack;
diff --git a/tests/Doctrine/Tests/DBAL/Performance/TypeConversionPerformanceTest.php b/tests/Doctrine/Tests/DBAL/Performance/TypeConversionPerformanceTest.php
index 6a76e90f897..7edd40dacd4 100644
--- a/tests/Doctrine/Tests/DBAL/Performance/TypeConversionPerformanceTest.php
+++ b/tests/Doctrine/Tests/DBAL/Performance/TypeConversionPerformanceTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Performance;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/AbstractMySQLPlatformTestCase.php b/tests/Doctrine/Tests/DBAL/Platforms/AbstractMySQLPlatformTestCase.php
index 2d59826272d..fdb3707c7ea 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/AbstractMySQLPlatformTestCase.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/AbstractMySQLPlatformTestCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/AbstractPlatformTestCase.php b/tests/Doctrine/Tests/DBAL/Platforms/AbstractPlatformTestCase.php
index 3ce6e1132c4..6925ff0a465 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/AbstractPlatformTestCase.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/AbstractPlatformTestCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\Common\EventManager;
@@ -289,8 +291,8 @@ protected function getBitAndComparisonExpressionSql(string $value1, string $valu
      */
     public function testGeneratesBitAndComparisonExpressionSql() : void
     {
-        $sql = $this->platform->getBitAndComparisonExpression(2, 4);
-        self::assertEquals($this->getBitAndComparisonExpressionSql(2, 4), $sql);
+        $sql = $this->platform->getBitAndComparisonExpression('2', '4');
+        self::assertEquals($this->getBitAndComparisonExpressionSql('2', '4'), $sql);
     }
 
     protected function getBitOrComparisonExpressionSql(string $value1, string $value2) : string
@@ -303,8 +305,8 @@ protected function getBitOrComparisonExpressionSql(string $value1, string $value
      */
     public function testGeneratesBitOrComparisonExpressionSql() : void
     {
-        $sql = $this->platform->getBitOrComparisonExpression(2, 4);
-        self::assertEquals($this->getBitOrComparisonExpressionSql(2, 4), $sql);
+        $sql = $this->platform->getBitOrComparisonExpression('2', '4');
+        self::assertEquals($this->getBitOrComparisonExpressionSql('2', '4'), $sql);
     }
 
     public function getGenerateConstraintUniqueIndexSql() : string
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/AbstractPostgreSqlPlatformTestCase.php b/tests/Doctrine/Tests/DBAL/Platforms/AbstractPostgreSqlPlatformTestCase.php
index 44c28018849..56cad4aab7e 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/AbstractPostgreSqlPlatformTestCase.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/AbstractPostgreSqlPlatformTestCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\Schema\Column;
@@ -140,8 +142,8 @@ public function testGeneratesSqlSnippets() : void
         self::assertEquals('SIMILAR TO', $this->platform->getRegexpExpression(), 'Regular expression operator is not correct');
         self::assertEquals('"', $this->platform->getIdentifierQuoteCharacter(), 'Identifier quote character is not correct');
         self::assertEquals('column1 || column2 || column3', $this->platform->getConcatExpression('column1', 'column2', 'column3'), 'Concatenation expression is not correct');
-        self::assertEquals('SUBSTRING(column FROM 5)', $this->platform->getSubstringExpression('column', 5), 'Substring expression without length is not correct');
-        self::assertEquals('SUBSTRING(column FROM 1 FOR 5)', $this->platform->getSubstringExpression('column', 1, 5), 'Substring expression with length is not correct');
+        self::assertEquals('SUBSTRING(column FROM 5)', $this->platform->getSubstringExpression('column', '5'), 'Substring expression without length is not correct');
+        self::assertEquals('SUBSTRING(column FROM 1 FOR 5)', $this->platform->getSubstringExpression('column', '1', '5'), 'Substring expression with length is not correct');
     }
 
     public function testGeneratesTransactionCommands() : void
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/AbstractSQLServerPlatformTestCase.php b/tests/Doctrine/Tests/DBAL/Platforms/AbstractSQLServerPlatformTestCase.php
index fb9e5765af2..a2c9eb085d8 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/AbstractSQLServerPlatformTestCase.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/AbstractSQLServerPlatformTestCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\DBALException;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/DB2PlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/DB2PlatformTest.php
index db2c444d1f5..72f13162142 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/DB2PlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/DB2PlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
@@ -321,7 +323,6 @@ public function testGeneratesDDLSnippets() : void
         self::assertEquals('DROP DATABASE foobar', $this->platform->getDropDatabaseSQL('foobar'));
         self::assertEquals('DECLARE GLOBAL TEMPORARY TABLE', $this->platform->getCreateTemporaryTableSnippetSQL());
         self::assertEquals('TRUNCATE foobar IMMEDIATE', $this->platform->getTruncateTableSQL('foobar'));
-        self::assertEquals('TRUNCATE foobar IMMEDIATE', $this->platform->getTruncateTableSQL('foobar'), true);
 
         $viewSql = 'SELECT * FROM footable';
         self::assertEquals('CREATE VIEW fooview AS ' . $viewSql, $this->platform->getCreateViewSQL('fooview', $viewSql));
@@ -344,28 +345,28 @@ public function testGeneratesSQLSnippets() : void
         self::assertEquals('CURRENT DATE', $this->platform->getCurrentDateSQL());
         self::assertEquals('CURRENT TIME', $this->platform->getCurrentTimeSQL());
         self::assertEquals('CURRENT TIMESTAMP', $this->platform->getCurrentTimestampSQL());
-        self::assertEquals("'1987/05/02' + 4 DAY", $this->platform->getDateAddDaysExpression("'1987/05/02'", 4));
-        self::assertEquals("'1987/05/02' + 12 HOUR", $this->platform->getDateAddHourExpression("'1987/05/02'", 12));
-        self::assertEquals("'1987/05/02' + 2 MINUTE", $this->platform->getDateAddMinutesExpression("'1987/05/02'", 2));
-        self::assertEquals("'1987/05/02' + 102 MONTH", $this->platform->getDateAddMonthExpression("'1987/05/02'", 102));
-        self::assertEquals("'1987/05/02' + (5 * 3) MONTH", $this->platform->getDateAddQuartersExpression("'1987/05/02'", 5));
-        self::assertEquals("'1987/05/02' + 1 SECOND", $this->platform->getDateAddSecondsExpression("'1987/05/02'", 1));
-        self::assertEquals("'1987/05/02' + (3 * 7) DAY", $this->platform->getDateAddWeeksExpression("'1987/05/02'", 3));
-        self::assertEquals("'1987/05/02' + 10 YEAR", $this->platform->getDateAddYearsExpression("'1987/05/02'", 10));
+        self::assertEquals("'1987/05/02' + 4 DAY", $this->platform->getDateAddDaysExpression("'1987/05/02'", '4'));
+        self::assertEquals("'1987/05/02' + 12 HOUR", $this->platform->getDateAddHourExpression("'1987/05/02'", '12'));
+        self::assertEquals("'1987/05/02' + 2 MINUTE", $this->platform->getDateAddMinutesExpression("'1987/05/02'", '2'));
+        self::assertEquals("'1987/05/02' + 102 MONTH", $this->platform->getDateAddMonthExpression("'1987/05/02'", '102'));
+        self::assertEquals("'1987/05/02' + (5 * 3) MONTH", $this->platform->getDateAddQuartersExpression("'1987/05/02'", '5'));
+        self::assertEquals("'1987/05/02' + 1 SECOND", $this->platform->getDateAddSecondsExpression("'1987/05/02'", '1'));
+        self::assertEquals("'1987/05/02' + (3 * 7) DAY", $this->platform->getDateAddWeeksExpression("'1987/05/02'", '3'));
+        self::assertEquals("'1987/05/02' + 10 YEAR", $this->platform->getDateAddYearsExpression("'1987/05/02'", '10'));
         self::assertEquals("DAYS('1987/05/02') - DAYS('1987/04/01')", $this->platform->getDateDiffExpression("'1987/05/02'", "'1987/04/01'"));
-        self::assertEquals("'1987/05/02' - 4 DAY", $this->platform->getDateSubDaysExpression("'1987/05/02'", 4));
-        self::assertEquals("'1987/05/02' - 12 HOUR", $this->platform->getDateSubHourExpression("'1987/05/02'", 12));
-        self::assertEquals("'1987/05/02' - 2 MINUTE", $this->platform->getDateSubMinutesExpression("'1987/05/02'", 2));
-        self::assertEquals("'1987/05/02' - 102 MONTH", $this->platform->getDateSubMonthExpression("'1987/05/02'", 102));
-        self::assertEquals("'1987/05/02' - (5 * 3) MONTH", $this->platform->getDateSubQuartersExpression("'1987/05/02'", 5));
-        self::assertEquals("'1987/05/02' - 1 SECOND", $this->platform->getDateSubSecondsExpression("'1987/05/02'", 1));
-        self::assertEquals("'1987/05/02' - (3 * 7) DAY", $this->platform->getDateSubWeeksExpression("'1987/05/02'", 3));
-        self::assertEquals("'1987/05/02' - 10 YEAR", $this->platform->getDateSubYearsExpression("'1987/05/02'", 10));
+        self::assertEquals("'1987/05/02' - 4 DAY", $this->platform->getDateSubDaysExpression("'1987/05/02'", '4'));
+        self::assertEquals("'1987/05/02' - 12 HOUR", $this->platform->getDateSubHourExpression("'1987/05/02'", '12'));
+        self::assertEquals("'1987/05/02' - 2 MINUTE", $this->platform->getDateSubMinutesExpression("'1987/05/02'", '2'));
+        self::assertEquals("'1987/05/02' - 102 MONTH", $this->platform->getDateSubMonthExpression("'1987/05/02'", '102'));
+        self::assertEquals("'1987/05/02' - (5 * 3) MONTH", $this->platform->getDateSubQuartersExpression("'1987/05/02'", '5'));
+        self::assertEquals("'1987/05/02' - 1 SECOND", $this->platform->getDateSubSecondsExpression("'1987/05/02'", '1'));
+        self::assertEquals("'1987/05/02' - (3 * 7) DAY", $this->platform->getDateSubWeeksExpression("'1987/05/02'", '3'));
+        self::assertEquals("'1987/05/02' - 10 YEAR", $this->platform->getDateSubYearsExpression("'1987/05/02'", '10'));
         self::assertEquals(' WITH RR USE AND KEEP UPDATE LOCKS', $this->platform->getForUpdateSQL());
         self::assertEquals('LOCATE(substring_column, string_column)', $this->platform->getLocateExpression('string_column', 'substring_column'));
-        self::assertEquals('LOCATE(substring_column, string_column, 1)', $this->platform->getLocateExpression('string_column', 'substring_column', 1));
-        self::assertEquals('SUBSTR(column, 5)', $this->platform->getSubstringExpression('column', 5));
-        self::assertEquals('SUBSTR(column, 5, 2)', $this->platform->getSubstringExpression('column', 5, 2));
+        self::assertEquals('LOCATE(substring_column, string_column, 1)', $this->platform->getLocateExpression('string_column', 'substring_column', '1'));
+        self::assertEquals('SUBSTR(column, 5)', $this->platform->getSubstringExpression('column', '5'));
+        self::assertEquals('SUBSTR(column, 5, 2)', $this->platform->getSubstringExpression('column', '5', '2'));
     }
 
     public function testModifiesLimitQuery() : void
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/MariaDb1027PlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/MariaDb1027PlatformTest.php
index 00b86088ad5..cf8493886b5 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/MariaDb1027PlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/MariaDb1027PlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/MySQL57PlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/MySQL57PlatformTest.php
index 2557562ab95..1513a6e36b1 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/MySQL57PlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/MySQL57PlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/MySqlPlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/MySqlPlatformTest.php
index e8007baf55f..4abddf2441b 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/MySqlPlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/MySqlPlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/OraclePlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/OraclePlatformTest.php
index 68d7c749a44..85d32449435 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/OraclePlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/OraclePlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\DBALException;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/PostgreSQL94PlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/PostgreSQL94PlatformTest.php
index 3439bb95868..4d18f199fc5 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/PostgreSQL94PlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/PostgreSQL94PlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/PostgreSqlPlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/PostgreSqlPlatformTest.php
index 0fe322d2225..1c53102ac9f 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/PostgreSqlPlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/PostgreSqlPlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/ReservedKeywordsValidatorTest.php b/tests/Doctrine/Tests/DBAL/Platforms/ReservedKeywordsValidatorTest.php
index 8d07f62274d..186cfdaeebc 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/ReservedKeywordsValidatorTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/ReservedKeywordsValidatorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\Platforms\Keywords\MySQLKeywords;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/SQLAnywherePlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/SQLAnywherePlatformTest.php
index 2c41a2f7b41..b3b1d48621f 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/SQLAnywherePlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/SQLAnywherePlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\DBALException;
@@ -338,7 +340,6 @@ public function testGeneratesDDLSnippets() : void
         self::assertEquals('STOP DATABASE "foobar" UNCONDITIONALLY', $this->platform->getStopDatabaseSQL('"foobar"'));
         self::assertEquals('STOP DATABASE "create" UNCONDITIONALLY', $this->platform->getStopDatabaseSQL('create'));
         self::assertEquals('TRUNCATE TABLE foobar', $this->platform->getTruncateTableSQL('foobar'));
-        self::assertEquals('TRUNCATE TABLE foobar', $this->platform->getTruncateTableSQL('foobar'), true);
 
         $viewSql = 'SELECT * FROM footable';
         self::assertEquals('CREATE VIEW fooview AS ' . $viewSql, $this->platform->getCreateViewSQL('fooview', $viewSql));
@@ -393,12 +394,12 @@ public function testGeneratesUniqueConstraintDeclarationSQL() : void
             'CONSTRAINT unique_constraint UNIQUE CLUSTERED (a, b)',
             $this->platform->getUniqueConstraintDeclarationSQL(
                 'unique_constraint',
-                new UniqueConstraint(null, ['a', 'b'], ['clustered'])
+                new UniqueConstraint('', ['a', 'b'], ['clustered'])
             )
         );
         self::assertEquals(
             'CONSTRAINT UNIQUE (a, b)',
-            $this->platform->getUniqueConstraintDeclarationSQL(null, new UniqueConstraint(null, ['a', 'b']))
+            $this->platform->getUniqueConstraintDeclarationSQL('', new UniqueConstraint('', ['a', 'b']))
         );
     }
 
@@ -647,31 +648,31 @@ public function testGeneratesSQLSnippets() : void
         self::assertEquals('CURRENT DATE', $this->platform->getCurrentDateSQL());
         self::assertEquals('CURRENT TIME', $this->platform->getCurrentTimeSQL());
         self::assertEquals('CURRENT TIMESTAMP', $this->platform->getCurrentTimestampSQL());
-        self::assertEquals("DATEADD(DAY, 4, '1987/05/02')", $this->platform->getDateAddDaysExpression("'1987/05/02'", 4));
-        self::assertEquals("DATEADD(HOUR, 12, '1987/05/02')", $this->platform->getDateAddHourExpression("'1987/05/02'", 12));
-        self::assertEquals("DATEADD(MINUTE, 2, '1987/05/02')", $this->platform->getDateAddMinutesExpression("'1987/05/02'", 2));
-        self::assertEquals("DATEADD(MONTH, 102, '1987/05/02')", $this->platform->getDateAddMonthExpression("'1987/05/02'", 102));
-        self::assertEquals("DATEADD(QUARTER, 5, '1987/05/02')", $this->platform->getDateAddQuartersExpression("'1987/05/02'", 5));
-        self::assertEquals("DATEADD(SECOND, 1, '1987/05/02')", $this->platform->getDateAddSecondsExpression("'1987/05/02'", 1));
-        self::assertEquals("DATEADD(WEEK, 3, '1987/05/02')", $this->platform->getDateAddWeeksExpression("'1987/05/02'", 3));
-        self::assertEquals("DATEADD(YEAR, 10, '1987/05/02')", $this->platform->getDateAddYearsExpression("'1987/05/02'", 10));
+        self::assertEquals("DATEADD(DAY, 4, '1987/05/02')", $this->platform->getDateAddDaysExpression("'1987/05/02'", '4'));
+        self::assertEquals("DATEADD(HOUR, 12, '1987/05/02')", $this->platform->getDateAddHourExpression("'1987/05/02'", '12'));
+        self::assertEquals("DATEADD(MINUTE, 2, '1987/05/02')", $this->platform->getDateAddMinutesExpression("'1987/05/02'", '2'));
+        self::assertEquals("DATEADD(MONTH, 102, '1987/05/02')", $this->platform->getDateAddMonthExpression("'1987/05/02'", '102'));
+        self::assertEquals("DATEADD(QUARTER, 5, '1987/05/02')", $this->platform->getDateAddQuartersExpression("'1987/05/02'", '5'));
+        self::assertEquals("DATEADD(SECOND, 1, '1987/05/02')", $this->platform->getDateAddSecondsExpression("'1987/05/02'", '1'));
+        self::assertEquals("DATEADD(WEEK, 3, '1987/05/02')", $this->platform->getDateAddWeeksExpression("'1987/05/02'", '3'));
+        self::assertEquals("DATEADD(YEAR, 10, '1987/05/02')", $this->platform->getDateAddYearsExpression("'1987/05/02'", '10'));
         self::assertEquals("DATEDIFF(day, '1987/04/01', '1987/05/02')", $this->platform->getDateDiffExpression("'1987/05/02'", "'1987/04/01'"));
-        self::assertEquals("DATEADD(DAY, -1 * 4, '1987/05/02')", $this->platform->getDateSubDaysExpression("'1987/05/02'", 4));
-        self::assertEquals("DATEADD(HOUR, -1 * 12, '1987/05/02')", $this->platform->getDateSubHourExpression("'1987/05/02'", 12));
-        self::assertEquals("DATEADD(MINUTE, -1 * 2, '1987/05/02')", $this->platform->getDateSubMinutesExpression("'1987/05/02'", 2));
-        self::assertEquals("DATEADD(MONTH, -1 * 102, '1987/05/02')", $this->platform->getDateSubMonthExpression("'1987/05/02'", 102));
-        self::assertEquals("DATEADD(QUARTER, -1 * 5, '1987/05/02')", $this->platform->getDateSubQuartersExpression("'1987/05/02'", 5));
-        self::assertEquals("DATEADD(SECOND, -1 * 1, '1987/05/02')", $this->platform->getDateSubSecondsExpression("'1987/05/02'", 1));
-        self::assertEquals("DATEADD(WEEK, -1 * 3, '1987/05/02')", $this->platform->getDateSubWeeksExpression("'1987/05/02'", 3));
-        self::assertEquals("DATEADD(YEAR, -1 * 10, '1987/05/02')", $this->platform->getDateSubYearsExpression("'1987/05/02'", 10));
+        self::assertEquals("DATEADD(DAY, -1 * 4, '1987/05/02')", $this->platform->getDateSubDaysExpression("'1987/05/02'", '4'));
+        self::assertEquals("DATEADD(HOUR, -1 * 12, '1987/05/02')", $this->platform->getDateSubHourExpression("'1987/05/02'", '12'));
+        self::assertEquals("DATEADD(MINUTE, -1 * 2, '1987/05/02')", $this->platform->getDateSubMinutesExpression("'1987/05/02'", '2'));
+        self::assertEquals("DATEADD(MONTH, -1 * 102, '1987/05/02')", $this->platform->getDateSubMonthExpression("'1987/05/02'", '102'));
+        self::assertEquals("DATEADD(QUARTER, -1 * 5, '1987/05/02')", $this->platform->getDateSubQuartersExpression("'1987/05/02'", '5'));
+        self::assertEquals("DATEADD(SECOND, -1 * 1, '1987/05/02')", $this->platform->getDateSubSecondsExpression("'1987/05/02'", '1'));
+        self::assertEquals("DATEADD(WEEK, -1 * 3, '1987/05/02')", $this->platform->getDateSubWeeksExpression("'1987/05/02'", '3'));
+        self::assertEquals("DATEADD(YEAR, -1 * 10, '1987/05/02')", $this->platform->getDateSubYearsExpression("'1987/05/02'", '10'));
         self::assertEquals('Y-m-d H:i:s.u', $this->platform->getDateTimeFormatString());
         self::assertEquals('H:i:s.u', $this->platform->getTimeFormatString());
         self::assertEquals('', $this->platform->getForUpdateSQL());
         self::assertEquals('LOCATE(string_column, substring_column)', $this->platform->getLocateExpression('string_column', 'substring_column'));
-        self::assertEquals('LOCATE(string_column, substring_column, 1)', $this->platform->getLocateExpression('string_column', 'substring_column', 1));
+        self::assertEquals('LOCATE(string_column, substring_column, 1)', $this->platform->getLocateExpression('string_column', 'substring_column', '1'));
         self::assertEquals("HASH(column, 'MD5')", $this->platform->getMd5Expression('column'));
-        self::assertEquals('SUBSTRING(column, 5)', $this->platform->getSubstringExpression('column', 5));
-        self::assertEquals('SUBSTRING(column, 5, 2)', $this->platform->getSubstringExpression('column', 5, 2));
+        self::assertEquals('SUBSTRING(column, 5)', $this->platform->getSubstringExpression('column', '5'));
+        self::assertEquals('SUBSTRING(column, 5, 2)', $this->platform->getSubstringExpression('column', '5', '2'));
         self::assertEquals('GLOBAL TEMPORARY', $this->platform->getTemporaryTableSQL());
         self::assertEquals(
             'LTRIM(column)',
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/SQLAzurePlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/SQLAzurePlatformTest.php
index 65b5e85f219..69eac4a127d 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/SQLAzurePlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/SQLAzurePlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\Platforms\SQLAzurePlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/SQLServer2012PlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/SQLServer2012PlatformTest.php
index 18a8a0ef1d2..a85e6ac5457 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/SQLServer2012PlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/SQLServer2012PlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\DBALException;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/SQLServerPlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/SQLServerPlatformTest.php
index cdbf83e88f3..98cbf2b1570 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/SQLServerPlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/SQLServerPlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\LockMode;
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/SqlitePlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/SqlitePlatformTest.php
index 24201953d4f..7d96bcbbb8a 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/SqlitePlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/SqlitePlatformTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Platforms;
 
 use Doctrine\DBAL\DBALException;
@@ -37,8 +39,8 @@ public function getGenerateTableWithMultiColumnUniqueIndexSql() : array
     public function testGeneratesSqlSnippets() : void
     {
         self::assertEquals('REGEXP', $this->platform->getRegexpExpression(), 'Regular expression operator is not correct');
-        self::assertEquals('SUBSTR(column, 5)', $this->platform->getSubstringExpression('column', 5), 'Substring expression without length is not correct');
-        self::assertEquals('SUBSTR(column, 0, 5)', $this->platform->getSubstringExpression('column', 0, 5), 'Substring expression with length is not correct');
+        self::assertEquals('SUBSTR(column, 5)', $this->platform->getSubstringExpression('column', '5'), 'Substring expression without length is not correct');
+        self::assertEquals('SUBSTR(column, 0, 5)', $this->platform->getSubstringExpression('column', '0', '5'), 'Substring expression with length is not correct');
     }
 
     public function testGeneratesTransactionCommands() : void
@@ -791,7 +793,7 @@ public function testQuotesTableNameInListTableForeignKeysSQL() : void
 
     public function testDateAddStaticNumberOfDays() : void
     {
-        self::assertSame("DATETIME(rentalBeginsOn,'+' || 12 || ' DAY')", $this->platform->getDateAddDaysExpression('rentalBeginsOn', 12));
+        self::assertSame("DATETIME(rentalBeginsOn,'+' || 12 || ' DAY')", $this->platform->getDateAddDaysExpression('rentalBeginsOn', '12'));
     }
 
     public function testDateAddNumberOfDaysFromColumn() : void
diff --git a/tests/Doctrine/Tests/DBAL/Portability/StatementTest.php b/tests/Doctrine/Tests/DBAL/Portability/StatementTest.php
index a7764107f52..ae7f6a385ee 100644
--- a/tests/Doctrine/Tests/DBAL/Portability/StatementTest.php
+++ b/tests/Doctrine/Tests/DBAL/Portability/StatementTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Portability;
 
 use Doctrine\DBAL\Driver\Statement as DriverStatement;
diff --git a/tests/Doctrine/Tests/DBAL/Query/Expression/CompositeExpressionTest.php b/tests/Doctrine/Tests/DBAL/Query/Expression/CompositeExpressionTest.php
index 0a8492f795f..61286726969 100644
--- a/tests/Doctrine/Tests/DBAL/Query/Expression/CompositeExpressionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Query/Expression/CompositeExpressionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Query\Expression;
 
 use Doctrine\DBAL\Query\Expression\CompositeExpression;
diff --git a/tests/Doctrine/Tests/DBAL/Query/Expression/ExpressionBuilderTest.php b/tests/Doctrine/Tests/DBAL/Query/Expression/ExpressionBuilderTest.php
index 817007d67d6..55a8b0a84f9 100644
--- a/tests/Doctrine/Tests/DBAL/Query/Expression/ExpressionBuilderTest.php
+++ b/tests/Doctrine/Tests/DBAL/Query/Expression/ExpressionBuilderTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Query\Expression;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Query/QueryBuilderTest.php b/tests/Doctrine/Tests/DBAL/Query/QueryBuilderTest.php
index 3f71454ce22..3ec7c1103f6 100644
--- a/tests/Doctrine/Tests/DBAL/Query/QueryBuilderTest.php
+++ b/tests/Doctrine/Tests/DBAL/Query/QueryBuilderTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Query;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/SQLParserUtilsTest.php b/tests/Doctrine/Tests/DBAL/SQLParserUtilsTest.php
index ea8d4dc0752..2113a37b0e9 100644
--- a/tests/Doctrine/Tests/DBAL/SQLParserUtilsTest.php
+++ b/tests/Doctrine/Tests/DBAL/SQLParserUtilsTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/ColumnDiffTest.php b/tests/Doctrine/Tests/DBAL/Schema/ColumnDiffTest.php
index 0bdaa85ef6d..a7d724cbea5 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/ColumnDiffTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/ColumnDiffTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\Schema\Column;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/ColumnTest.php b/tests/Doctrine/Tests/DBAL/Schema/ColumnTest.php
index 0997ce26319..0680e7bec35 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/ColumnTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/ColumnTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\MySqlPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/ComparatorTest.php b/tests/Doctrine/Tests/DBAL/Schema/ComparatorTest.php
index f6112f03fc0..2fa7141a89d 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/ComparatorTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/ComparatorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\Schema\Column;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/DB2SchemaManagerTest.php b/tests/Doctrine/Tests/DBAL/Schema/DB2SchemaManagerTest.php
index be46d742949..46b8fd3949e 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/DB2SchemaManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/DB2SchemaManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\Common\EventManager;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/ForeignKeyConstraintTest.php b/tests/Doctrine/Tests/DBAL/Schema/ForeignKeyConstraintTest.php
index f0b115ddc4f..f1f5c6aa05e 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/ForeignKeyConstraintTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/ForeignKeyConstraintTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\Schema\ForeignKeyConstraint;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/IndexTest.php b/tests/Doctrine/Tests/DBAL/Schema/IndexTest.php
index d21e676b273..07831cbc052 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/IndexTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/IndexTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\Schema\Index;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/MySqlSchemaManagerTest.php b/tests/Doctrine/Tests/DBAL/Schema/MySqlSchemaManagerTest.php
index 5c8881decb4..96ca5123ffb 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/MySqlSchemaManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/MySqlSchemaManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\Common\EventManager;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/Platforms/MySQLSchemaTest.php b/tests/Doctrine/Tests/DBAL/Schema/Platforms/MySQLSchemaTest.php
index 4cf69f28f7c..fcffe6f1a8c 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/Platforms/MySQLSchemaTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/Platforms/MySQLSchemaTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema\Platforms;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/SchemaDiffTest.php b/tests/Doctrine/Tests/DBAL/Schema/SchemaDiffTest.php
index 87146c2f001..e3e09c88bbd 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/SchemaDiffTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/SchemaDiffTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/SchemaTest.php b/tests/Doctrine/Tests/DBAL/Schema/SchemaTest.php
index 69796236235..a20602836ca 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/SchemaTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/SchemaTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\Schema\Schema;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/SequenceTest.php b/tests/Doctrine/Tests/DBAL/Schema/SequenceTest.php
index d13d0a908a6..e1ad3941379 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/SequenceTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/SequenceTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\Schema\Sequence;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/SqliteSchemaManagerTest.php b/tests/Doctrine/Tests/DBAL/Schema/SqliteSchemaManagerTest.php
index 3677212f240..63944ec9f34 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/SqliteSchemaManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/SqliteSchemaManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/Synchronizer/SingleDatabaseSynchronizerTest.php b/tests/Doctrine/Tests/DBAL/Schema/Synchronizer/SingleDatabaseSynchronizerTest.php
index ad24ca599a6..b687ba34cc4 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/Synchronizer/SingleDatabaseSynchronizerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/Synchronizer/SingleDatabaseSynchronizerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema\Synchronizer;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/TableDiffTest.php b/tests/Doctrine/Tests/DBAL/Schema/TableDiffTest.php
index 7ae17019f83..8d37ca1dcc6 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/TableDiffTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/TableDiffTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/TableTest.php b/tests/Doctrine/Tests/DBAL/Schema/TableTest.php
index 112fef0a81e..df25b8da091 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/TableTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/TableTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema;
 
 use Doctrine\DBAL\DBALException;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/Visitor/CreateSchemaSqlCollectorTest.php b/tests/Doctrine/Tests/DBAL/Schema/Visitor/CreateSchemaSqlCollectorTest.php
index b70d2193a37..cd173df6bb1 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/Visitor/CreateSchemaSqlCollectorTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/Visitor/CreateSchemaSqlCollectorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/Visitor/DropSchemaSqlCollectorTest.php b/tests/Doctrine/Tests/DBAL/Schema/Visitor/DropSchemaSqlCollectorTest.php
index ea265396333..4336a946fff 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/Visitor/DropSchemaSqlCollectorTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/Visitor/DropSchemaSqlCollectorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/Visitor/RemoveNamespacedAssetsTest.php b/tests/Doctrine/Tests/DBAL/Schema/Visitor/RemoveNamespacedAssetsTest.php
index 982da52ec44..7f367f11d37 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/Visitor/RemoveNamespacedAssetsTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/Visitor/RemoveNamespacedAssetsTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Platforms\MySqlPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Schema/Visitor/SchemaSqlCollectorTest.php b/tests/Doctrine/Tests/DBAL/Schema/Visitor/SchemaSqlCollectorTest.php
index 34e2896de29..9455dc65769 100644
--- a/tests/Doctrine/Tests/DBAL/Schema/Visitor/SchemaSqlCollectorTest.php
+++ b/tests/Doctrine/Tests/DBAL/Schema/Visitor/SchemaSqlCollectorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Schema\Visitor;
 
 use Doctrine\DBAL\Platforms\MySqlPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Sharding/PoolingShardConnectionTest.php b/tests/Doctrine/Tests/DBAL/Sharding/PoolingShardConnectionTest.php
index c782b06b919..e8a88935c5e 100644
--- a/tests/Doctrine/Tests/DBAL/Sharding/PoolingShardConnectionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Sharding/PoolingShardConnectionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Sharding;
 
 use Doctrine\DBAL\DriverManager;
diff --git a/tests/Doctrine/Tests/DBAL/Sharding/PoolingShardManagerTest.php b/tests/Doctrine/Tests/DBAL/Sharding/PoolingShardManagerTest.php
index 01db26773f3..3d582d9e6c8 100644
--- a/tests/Doctrine/Tests/DBAL/Sharding/PoolingShardManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Sharding/PoolingShardManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Sharding;
 
 use Doctrine\DBAL\Sharding\PoolingShardConnection;
diff --git a/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/AbstractTestCase.php b/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/AbstractTestCase.php
index b0439d5dfe2..ef36ada364a 100644
--- a/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/AbstractTestCase.php
+++ b/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/AbstractTestCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Sharding\SQLAzure;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/FunctionalTest.php b/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/FunctionalTest.php
index 6e31d8716ed..67bf2369494 100644
--- a/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/FunctionalTest.php
+++ b/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/FunctionalTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Sharding\SQLAzure;
 
 use Doctrine\DBAL\Sharding\SQLAzure\SQLAzureFederationsSynchronizer;
diff --git a/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/MultiTenantVisitorTest.php b/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/MultiTenantVisitorTest.php
index 3549cf40b0e..019ef12a2a0 100644
--- a/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/MultiTenantVisitorTest.php
+++ b/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/MultiTenantVisitorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Sharding\SQLAzure;
 
 use Doctrine\DBAL\Platforms\SQLAzurePlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/SQLAzureFederationsSynchronizerTest.php b/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/SQLAzureFederationsSynchronizerTest.php
index 2185a9fc8d1..ce8ee7ba065 100644
--- a/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/SQLAzureFederationsSynchronizerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/SQLAzureFederationsSynchronizerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Sharding\SQLAzure;
 
 use Doctrine\DBAL\Sharding\SQLAzure\SQLAzureFederationsSynchronizer;
diff --git a/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/SQLAzureShardManagerTest.php b/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/SQLAzureShardManagerTest.php
index 6dcbad5f356..53c6f279196 100644
--- a/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/SQLAzureShardManagerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Sharding/SQLAzure/SQLAzureShardManagerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Sharding\SQLAzure;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Sharding/ShardChoser/MultiTenantShardChoserTest.php b/tests/Doctrine/Tests/DBAL/Sharding/ShardChoser/MultiTenantShardChoserTest.php
index aa15f91d3cc..97e9e21ef33 100644
--- a/tests/Doctrine/Tests/DBAL/Sharding/ShardChoser/MultiTenantShardChoserTest.php
+++ b/tests/Doctrine/Tests/DBAL/Sharding/ShardChoser/MultiTenantShardChoserTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Sharding\ShardChoser;
 
 use Doctrine\DBAL\Sharding\PoolingShardConnection;
diff --git a/tests/Doctrine/Tests/DBAL/StatementTest.php b/tests/Doctrine/Tests/DBAL/StatementTest.php
index 1d152bcb56b..b61f825b51a 100644
--- a/tests/Doctrine/Tests/DBAL/StatementTest.php
+++ b/tests/Doctrine/Tests/DBAL/StatementTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL;
 
 use Doctrine\DBAL\Configuration;
diff --git a/tests/Doctrine/Tests/DBAL/Tools/Console/RunSqlCommandTest.php b/tests/Doctrine/Tests/DBAL/Tools/Console/RunSqlCommandTest.php
index 21eab4203ba..ae876f96367 100644
--- a/tests/Doctrine/Tests/DBAL/Tools/Console/RunSqlCommandTest.php
+++ b/tests/Doctrine/Tests/DBAL/Tools/Console/RunSqlCommandTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Tools\Console;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DBAL/Tools/DumperTest.php b/tests/Doctrine/Tests/DBAL/Tools/DumperTest.php
index ba99024231b..31015f7fca1 100644
--- a/tests/Doctrine/Tests/DBAL/Tools/DumperTest.php
+++ b/tests/Doctrine/Tests/DBAL/Tools/DumperTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Tools;
 
 use ArrayIterator;
diff --git a/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ChildClass.php b/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ChildClass.php
index 19e7020c340..106f265680e 100644
--- a/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ChildClass.php
+++ b/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ChildClass.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Tools\TestAsset;
 
 final class ChildClass extends ParentClass
diff --git a/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ChildWithSameAttributesClass.php b/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ChildWithSameAttributesClass.php
index 623a6c02690..3964a48e7d0 100644
--- a/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ChildWithSameAttributesClass.php
+++ b/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ChildWithSameAttributesClass.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Tools\TestAsset;
 
 final class ChildWithSameAttributesClass extends ParentClass
diff --git a/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ParentClass.php b/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ParentClass.php
index 62831aef198..cf4f2c099c1 100644
--- a/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ParentClass.php
+++ b/tests/Doctrine/Tests/DBAL/Tools/TestAsset/ParentClass.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Tools\TestAsset;
 
 abstract class ParentClass
diff --git a/tests/Doctrine/Tests/DBAL/Types/ArrayTest.php b/tests/Doctrine/Tests/DBAL/Types/ArrayTest.php
index bc6ab4d413f..6ddd6c0920d 100644
--- a/tests/Doctrine/Tests/DBAL/Types/ArrayTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/ArrayTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Types/BaseDateTypeTestCase.php b/tests/Doctrine/Tests/DBAL/Types/BaseDateTypeTestCase.php
index 5f5b412e249..6e1e2ace82b 100644
--- a/tests/Doctrine/Tests/DBAL/Types/BaseDateTypeTestCase.php
+++ b/tests/Doctrine/Tests/DBAL/Types/BaseDateTypeTestCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Types/BinaryTest.php b/tests/Doctrine/Tests/DBAL/Types/BinaryTest.php
index 259e3daa053..eb0341bcd85 100644
--- a/tests/Doctrine/Tests/DBAL/Types/BinaryTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/BinaryTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\ParameterType;
diff --git a/tests/Doctrine/Tests/DBAL/Types/BlobTest.php b/tests/Doctrine/Tests/DBAL/Types/BlobTest.php
index 40fb111f1ba..f31369e6fd6 100644
--- a/tests/Doctrine/Tests/DBAL/Types/BlobTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/BlobTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Types/BooleanTest.php b/tests/Doctrine/Tests/DBAL/Types/BooleanTest.php
index b5e25c2a77b..0c012b83c94 100644
--- a/tests/Doctrine/Tests/DBAL/Types/BooleanTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/BooleanTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Types/ConversionExceptionTest.php b/tests/Doctrine/Tests/DBAL/Types/ConversionExceptionTest.php
index e7fa8a4be03..acc0f91130d 100644
--- a/tests/Doctrine/Tests/DBAL/Types/ConversionExceptionTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/ConversionExceptionTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Types\ConversionException;
diff --git a/tests/Doctrine/Tests/DBAL/Types/DateImmutableTypeTest.php b/tests/Doctrine/Tests/DBAL/Types/DateImmutableTypeTest.php
index d023e6bc1ba..7d383f46a8c 100644
--- a/tests/Doctrine/Tests/DBAL/Types/DateImmutableTypeTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/DateImmutableTypeTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Types/DateIntervalTest.php b/tests/Doctrine/Tests/DBAL/Types/DateIntervalTest.php
index 7b2c09aca9f..67b534a4b58 100644
--- a/tests/Doctrine/Tests/DBAL/Types/DateIntervalTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/DateIntervalTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateInterval;
diff --git a/tests/Doctrine/Tests/DBAL/Types/DateTest.php b/tests/Doctrine/Tests/DBAL/Types/DateTest.php
index 73e426ea41c..866e930f1bb 100644
--- a/tests/Doctrine/Tests/DBAL/Types/DateTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/DateTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Types/DateTimeImmutableTypeTest.php b/tests/Doctrine/Tests/DBAL/Types/DateTimeImmutableTypeTest.php
index 6ace4b4c4e8..92c29140dbc 100644
--- a/tests/Doctrine/Tests/DBAL/Types/DateTimeImmutableTypeTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/DateTimeImmutableTypeTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Types/DateTimeTest.php b/tests/Doctrine/Tests/DBAL/Types/DateTimeTest.php
index ba7a661c8d9..34df91b0f4e 100644
--- a/tests/Doctrine/Tests/DBAL/Types/DateTimeTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/DateTimeTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Types/DateTimeTzImmutableTypeTest.php b/tests/Doctrine/Tests/DBAL/Types/DateTimeTzImmutableTypeTest.php
index 808dfaf50ed..65cadef8de1 100644
--- a/tests/Doctrine/Tests/DBAL/Types/DateTimeTzImmutableTypeTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/DateTimeTzImmutableTypeTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Types/DateTimeTzTest.php b/tests/Doctrine/Tests/DBAL/Types/DateTimeTzTest.php
index 72ccaf87d05..d380f75b196 100644
--- a/tests/Doctrine/Tests/DBAL/Types/DateTimeTzTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/DateTimeTzTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Types/DecimalTest.php b/tests/Doctrine/Tests/DBAL/Types/DecimalTest.php
index 1528dfd86d9..d1a30b4be59 100644
--- a/tests/Doctrine/Tests/DBAL/Types/DecimalTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/DecimalTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Types/FloatTest.php b/tests/Doctrine/Tests/DBAL/Types/FloatTest.php
index 4934f716c0f..962cd98c458 100644
--- a/tests/Doctrine/Tests/DBAL/Types/FloatTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/FloatTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Types/GuidTypeTest.php b/tests/Doctrine/Tests/DBAL/Types/GuidTypeTest.php
index df265d8541a..f022f107d4b 100644
--- a/tests/Doctrine/Tests/DBAL/Types/GuidTypeTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/GuidTypeTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Types/IntegerTest.php b/tests/Doctrine/Tests/DBAL/Types/IntegerTest.php
index e4ac718c4ea..5795a3dd8a3 100644
--- a/tests/Doctrine/Tests/DBAL/Types/IntegerTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/IntegerTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Types/JsonArrayTest.php b/tests/Doctrine/Tests/DBAL/Types/JsonArrayTest.php
index 2ee5e9fc45e..baa8b953f48 100644
--- a/tests/Doctrine/Tests/DBAL/Types/JsonArrayTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/JsonArrayTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\ParameterType;
diff --git a/tests/Doctrine/Tests/DBAL/Types/JsonTest.php b/tests/Doctrine/Tests/DBAL/Types/JsonTest.php
index 4a5ff3c28c0..b89d173d215 100644
--- a/tests/Doctrine/Tests/DBAL/Types/JsonTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/JsonTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\ParameterType;
diff --git a/tests/Doctrine/Tests/DBAL/Types/ObjectTest.php b/tests/Doctrine/Tests/DBAL/Types/ObjectTest.php
index da9481d105a..6b6347dafcb 100644
--- a/tests/Doctrine/Tests/DBAL/Types/ObjectTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/ObjectTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Types/SmallIntTest.php b/tests/Doctrine/Tests/DBAL/Types/SmallIntTest.php
index b1731a99578..77bbe2d3246 100644
--- a/tests/Doctrine/Tests/DBAL/Types/SmallIntTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/SmallIntTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Types/StringTest.php b/tests/Doctrine/Tests/DBAL/Types/StringTest.php
index 6b4aac786a4..b15ea498cb6 100644
--- a/tests/Doctrine/Tests/DBAL/Types/StringTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/StringTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/DBAL/Types/TimeImmutableTypeTest.php b/tests/Doctrine/Tests/DBAL/Types/TimeImmutableTypeTest.php
index ba087f19f40..dfd0a0d0e97 100644
--- a/tests/Doctrine/Tests/DBAL/Types/TimeImmutableTypeTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/TimeImmutableTypeTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Types/TimeTest.php b/tests/Doctrine/Tests/DBAL/Types/TimeTest.php
index a75544b650e..f2c89d095b6 100644
--- a/tests/Doctrine/Tests/DBAL/Types/TimeTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/TimeTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use Doctrine\DBAL\Types\ConversionException;
diff --git a/tests/Doctrine/Tests/DBAL/Types/VarDateTimeImmutableTypeTest.php b/tests/Doctrine/Tests/DBAL/Types/VarDateTimeImmutableTypeTest.php
index d3609fe2bac..83133a885de 100644
--- a/tests/Doctrine/Tests/DBAL/Types/VarDateTimeImmutableTypeTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/VarDateTimeImmutableTypeTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateTime;
diff --git a/tests/Doctrine/Tests/DBAL/Types/VarDateTimeTest.php b/tests/Doctrine/Tests/DBAL/Types/VarDateTimeTest.php
index 7fe10cb2ba3..6051b5b5790 100644
--- a/tests/Doctrine/Tests/DBAL/Types/VarDateTimeTest.php
+++ b/tests/Doctrine/Tests/DBAL/Types/VarDateTimeTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL\Types;
 
 use DateTime;
@@ -21,6 +23,10 @@ class VarDateTimeTest extends DbalTestCase
     protected function setUp() : void
     {
         $this->platform = $this->createMock(AbstractPlatform::class);
+        $this->platform->expects($this->any())
+            ->method('getDateTimeFormatString')
+            ->will($this->returnValue('U'));
+
         if (! Type::hasType('vardatetime')) {
             Type::addType('vardatetime', VarDateTimeType::class);
         }
@@ -31,7 +37,7 @@ public function testDateTimeConvertsToDatabaseValue() : void
     {
         $date = new DateTime('1985-09-01 10:10:10');
 
-        $expected = $date->format($this->platform->getDateTimeTzFormatString());
+        $expected = $date->format($this->platform->getDateTimeFormatString());
         $actual   = $this->type->convertToDatabaseValue($date, $this->platform);
 
         self::assertEquals($expected, $actual);
diff --git a/tests/Doctrine/Tests/DBAL/UtilTest.php b/tests/Doctrine/Tests/DBAL/UtilTest.php
index 92f63872f15..a70f638ca2b 100644
--- a/tests/Doctrine/Tests/DBAL/UtilTest.php
+++ b/tests/Doctrine/Tests/DBAL/UtilTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\DBAL;
 
 use Doctrine\DBAL\Driver\OCI8\OCI8Statement;
diff --git a/tests/Doctrine/Tests/DbalFunctionalTestCase.php b/tests/Doctrine/Tests/DbalFunctionalTestCase.php
index 16aa747c20e..036e1c92f06 100644
--- a/tests/Doctrine/Tests/DbalFunctionalTestCase.php
+++ b/tests/Doctrine/Tests/DbalFunctionalTestCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests;
 
 use Doctrine\DBAL\Connection;
diff --git a/tests/Doctrine/Tests/DbalPerformanceTestCase.php b/tests/Doctrine/Tests/DbalPerformanceTestCase.php
index ac0beb3c5de..19381ba2625 100644
--- a/tests/Doctrine/Tests/DbalPerformanceTestCase.php
+++ b/tests/Doctrine/Tests/DbalPerformanceTestCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests;
 
 use function microtime;
diff --git a/tests/Doctrine/Tests/DbalPerformanceTestListener.php b/tests/Doctrine/Tests/DbalPerformanceTestListener.php
index e9265c0f35f..6e4206289ad 100644
--- a/tests/Doctrine/Tests/DbalPerformanceTestListener.php
+++ b/tests/Doctrine/Tests/DbalPerformanceTestListener.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests;
 
 use PHPUnit\Framework\Test;
diff --git a/tests/Doctrine/Tests/DbalTestCase.php b/tests/Doctrine/Tests/DbalTestCase.php
index 8664141c03e..a059eae7745 100644
--- a/tests/Doctrine/Tests/DbalTestCase.php
+++ b/tests/Doctrine/Tests/DbalTestCase.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests;
 
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Doctrine/Tests/TestUtil.php b/tests/Doctrine/Tests/TestUtil.php
index b5f4dd010c2..7a1f74b95d6 100644
--- a/tests/Doctrine/Tests/TestUtil.php
+++ b/tests/Doctrine/Tests/TestUtil.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests;
 
 use Doctrine\DBAL\Connection;
@@ -160,7 +162,7 @@ private static function getParamsForTemporaryConnection() : array
             'password' => $GLOBALS['tmpdb_password'],
             'host' => $GLOBALS['tmpdb_host'],
             'dbname' => null,
-            'port' => $GLOBALS['tmpdb_port'],
+            'port' => (int) $GLOBALS['tmpdb_port'],
         ];
 
         if (isset($GLOBALS['tmpdb_name'])) {
@@ -189,7 +191,7 @@ private static function getParamsForMainConnection() : array
             'password' => $GLOBALS['db_password'],
             'host' => $GLOBALS['db_host'],
             'dbname' => $GLOBALS['db_name'],
-            'port' => $GLOBALS['db_port'],
+            'port' => (int) $GLOBALS['db_port'],
         ];
 
         if (isset($GLOBALS['db_server'])) {
diff --git a/tests/Doctrine/Tests/Types/CommentedType.php b/tests/Doctrine/Tests/Types/CommentedType.php
index cbe98b2324b..0b02bcef995 100644
--- a/tests/Doctrine/Tests/Types/CommentedType.php
+++ b/tests/Doctrine/Tests/Types/CommentedType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;
diff --git a/tests/Doctrine/Tests/Types/MySqlPointType.php b/tests/Doctrine/Tests/Types/MySqlPointType.php
index f4740769b8b..46b9121c628 100644
--- a/tests/Doctrine/Tests/Types/MySqlPointType.php
+++ b/tests/Doctrine/Tests/Types/MySqlPointType.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Doctrine\Tests\Types;
 
 use Doctrine\DBAL\Platforms\AbstractPlatform;