[#1295] Add Cockroach DBMS detection and a DbmsDialect implementation

CHANGELOG.md

@@ -32,6 +32,7 @@ None yet
 * Improve dialect detection for MariaDB dialects
 * Workaround Hibernate proxy field access bug for non-pk relations
 * Fix issues with de-serializing of singular entity view attributes that use a collection type
+* Add Cockroach DBMS detection and a `DbmsDialect` implementation
 
 ### Backwards-incompatible changes
 

core/impl/src/main/java/com/blazebit/persistence/impl/CriteriaBuilderConfigurationImpl.java

@@ -18,6 +18,7 @@
 
 import com.blazebit.persistence.ConfigurationProperties;
 import com.blazebit.persistence.CriteriaBuilderFactory;
+import com.blazebit.persistence.impl.dialect.CockroachSQLDbmsDialect;
 import com.blazebit.persistence.impl.dialect.DB2DbmsDialect;
 import com.blazebit.persistence.impl.dialect.DefaultDbmsDialect;
 import com.blazebit.persistence.impl.dialect.H2DbmsDialect;
@@ -1840,6 +1841,7 @@ private void loadDbmsDialects() {
         registerDialect("postgresql", new PostgreSQLDbmsDialect());
         registerDialect("oracle", new OracleDbmsDialect());
         registerDialect("microsoft", new MSSQLDbmsDialect());
+        registerDialect("cockroach", new CockroachSQLDbmsDialect());
     }
 
     private void loadDefaultProperties() {

core/impl/src/main/java/com/blazebit/persistence/impl/dialect/CockroachSQLDbmsDialect.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2014 - 2021 Blazebit.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.blazebit.persistence.impl.dialect;
+
+import com.blazebit.persistence.spi.OrderByElement;
+
+import java.util.Map;
+
+/**
+ * @author Christian Beikov
+ * @since 1.6.0
+ */
+public class CockroachSQLDbmsDialect extends PostgreSQLDbmsDialect {
+
+    public CockroachSQLDbmsDialect() {
+    }
+
+    public CockroachSQLDbmsDialect(Map<Class<?>, String> childSqlTypes) {
+        super(childSqlTypes);
+    }
+
+    @Override
+    public void appendOrderByElement(StringBuilder sqlSb, OrderByElement element, String[] aliases) {
+        if (!element.isNullable()) {
+            super.appendOrderByElement(sqlSb, element, aliases);
+        } else {
+            appendEmulatedOrderByElementWithNulls(sqlSb, element, aliases);
+        }
+    }
+}

integration/hibernate-base/src/main/java/com/blazebit/persistence/integration/hibernate/base/function/AbstractHibernateEntityManagerFactoryIntegrator.java

@@ -156,6 +156,14 @@ protected String getDbmsName(EntityManagerFactory emf, EntityManager em, Dialect
         } else if (dialect instanceof InterbaseDialect) {
             return "interbase";
         } else {
+            try {
+                Class<?> cockroachDialect = dialect.getClass().getClassLoader().loadClass("org.hibernate.dialect.CockroachDB192Dialect");
+                if (cockroachDialect.isInstance(dialect)) {
+                    return "cockroach";
+                }
+            } catch (ClassNotFoundException e) {
+                // Ignore
+            }
             return null;
         }
     }