[SPARK-39339][SQL] Support TimestampNTZ type in JDBC data source

docs/sql-data-sources-jdbc.md

@@ -103,7 +103,7 @@ logging into the data sources.
     <td>(none)</td>
     <td>
       A prefix that will form the final query together with <code>query</code>.
-      As the specified <code>query</code> will be parenthesized as a subquery in the <code>FROM</code> clause and some databases do not 
+      As the specified <code>query</code> will be parenthesized as a subquery in the <code>FROM</code> clause and some databases do not
       support all clauses in subqueries, the <code>prepareQuery</code> property offers a way to run such complex queries.
       As an example, spark will issue a query of the following form to the JDBC Source.<br><br>
       <code>&lt;prepareQuery&gt; SELECT &lt;columns&gt; FROM (&lt;user_specified_query&gt;) spark_gen_alias</code><br><br>
@@ -340,10 +340,19 @@ logging into the data sources.
     <td>
       The name of the JDBC connection provider to use to connect to this URL, e.g. <code>db2</code>, <code>mssql</code>.
       Must be one of the providers loaded with the JDBC data source. Used to disambiguate when more than one provider can handle
-      the specified driver and options. The selected provider must not be disabled by <code>spark.sql.sources.disabledJdbcConnProviderList</code>. 
+      the specified driver and options. The selected provider must not be disabled by <code>spark.sql.sources.disabledJdbcConnProviderList</code>.
     </td>
     <td>read/write</td>
- </tr>  
+  </tr>
+  <tr>
+    <td><code>inferTimestampNTZType</code></td>
+    <td>false</td>
+    <td>
+      When the option is set to <code>true</code>, all timestamps are inferred as TIMESTAMP WITHOUT TIME ZONE.
+      Otherwise, timestamps are read as TIMESTAMP with local time zone.
+    </td>
+    <td>read</td>
+  </tr>
 </table>
 
 Note that kerberos authentication with keytab is not always supported by the JDBC driver.<br>

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/jdbc/JDBCOptions.scala

@@ -226,6 +226,9 @@ class JDBCOptions(
   // The prefix that is added to the query sent to the JDBC database.
   // This is required to support some complex queries with some JDBC databases.
   val prepareQuery = parameters.get(JDBC_PREPARE_QUERY).map(_ + " ").getOrElse("")
+
+  // Infers timestamp values as TimestampNTZ type when reading data.
+  val inferTimestampNTZType = parameters.getOrElse(JDBC_INFER_TIMESTAMP_NTZ, "false").toBoolean
 }
 
 class JdbcOptionsInWrite(
@@ -287,4 +290,5 @@ object JDBCOptions {
   val JDBC_REFRESH_KRB5_CONFIG = newOption("refreshKrb5Config")
   val JDBC_CONNECTION_PROVIDER = newOption("connectionProvider")
   val JDBC_PREPARE_QUERY = newOption("prepareQuery")
+  val JDBC_INFER_TIMESTAMP_NTZ = newOption("inferTimestampNTZType")
 }

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/jdbc/JDBCRDD.scala

@@ -67,7 +67,8 @@ object JDBCRDD extends Logging {
         statement.setQueryTimeout(options.queryTimeout)
         val rs = statement.executeQuery()
         try {
-          JdbcUtils.getSchema(rs, dialect, alwaysNullable = true)
+          JdbcUtils.getSchema(rs, dialect, alwaysNullable = true,
+            isTimestampNTZ = options.inferTimestampNTZType)
         } finally {
           rs.close()
         }

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/jdbc/JdbcUtils.scala

@@ -38,7 +38,7 @@ import org.apache.spark.sql.catalyst.encoders.RowEncoder
 import org.apache.spark.sql.catalyst.expressions.SpecificInternalRow
 import org.apache.spark.sql.catalyst.parser.CatalystSqlParser
 import org.apache.spark.sql.catalyst.util.{CaseInsensitiveMap, DateTimeUtils, GenericArrayData}
-import org.apache.spark.sql.catalyst.util.DateTimeUtils.{instantToMicros, localDateToDays, toJavaDate, toJavaTimestamp}
+import org.apache.spark.sql.catalyst.util.DateTimeUtils.{instantToMicros, localDateTimeToMicros, localDateToDays, toJavaDate, toJavaTimestamp}
 import org.apache.spark.sql.connector.catalog.TableChange
 import org.apache.spark.sql.connector.catalog.index.{SupportsIndex, TableIndex}
 import org.apache.spark.sql.connector.expressions.NamedReference
@@ -150,6 +150,10 @@ object JdbcUtils extends Logging with SQLConfHelper {
       case StringType => Option(JdbcType("TEXT", java.sql.Types.CLOB))
       case BinaryType => Option(JdbcType("BLOB", java.sql.Types.BLOB))
       case TimestampType => Option(JdbcType("TIMESTAMP", java.sql.Types.TIMESTAMP))
+      // This is a common case of timestamp without time zone. Most of the databases either only
+      // support TIMESTAMP type or use TIMESTAMP as an alias for TIMESTAMP WITHOUT TIME ZONE.
+      // Note that some dialects override this setting, e.g. as SQL Server.
+      case TimestampNTZType => Option(JdbcType("TIMESTAMP", java.sql.Types.TIMESTAMP))
       case DateType => Option(JdbcType("DATE", java.sql.Types.DATE))
       case t: DecimalType => Option(
         JdbcType(s"DECIMAL(${t.precision},${t.scale})", java.sql.Types.DECIMAL))
@@ -173,7 +177,8 @@ object JdbcUtils extends Logging with SQLConfHelper {
       sqlType: Int,
       precision: Int,
       scale: Int,
-      signed: Boolean): DataType = {
+      signed: Boolean,
+      isTimestampNTZ: Boolean): DataType = {
     val answer = sqlType match {
       // scalastyle:off
       case java.sql.Types.ARRAY         => null
@@ -215,6 +220,8 @@ object JdbcUtils extends Logging with SQLConfHelper {
       case java.sql.Types.TIME          => TimestampType
       case java.sql.Types.TIME_WITH_TIMEZONE
                                         => null
+      case java.sql.Types.TIMESTAMP
+        if isTimestampNTZ               => TimestampNTZType
       case java.sql.Types.TIMESTAMP     => TimestampType
       case java.sql.Types.TIMESTAMP_WITH_TIMEZONE
                                         => null
@@ -243,7 +250,8 @@ object JdbcUtils extends Logging with SQLConfHelper {
         conn.prepareStatement(options.prepareQuery + dialect.getSchemaQuery(options.tableOrQuery))
       try {
         statement.setQueryTimeout(options.queryTimeout)
-        Some(getSchema(statement.executeQuery(), dialect))
+        Some(getSchema(statement.executeQuery(), dialect,
+          isTimestampNTZ = options.inferTimestampNTZType))
       } catch {
         case _: SQLException => None
       } finally {
@@ -258,13 +266,15 @@ object JdbcUtils extends Logging with SQLConfHelper {
    * Takes a [[ResultSet]] and returns its Catalyst schema.
    *
    * @param alwaysNullable If true, all the columns are nullable.
+   * @param isTimestampNTZ If true, all timestamp columns are interpreted as TIMESTAMP_NTZ.
    * @return A [[StructType]] giving the Catalyst schema.
    * @throws SQLException if the schema contains an unsupported type.
    */
   def getSchema(
       resultSet: ResultSet,
       dialect: JdbcDialect,
-      alwaysNullable: Boolean = false): StructType = {
+      alwaysNullable: Boolean = false,
+      isTimestampNTZ: Boolean = false): StructType = {
     val rsmd = resultSet.getMetaData
     val ncols = rsmd.getColumnCount
     val fields = new Array[StructField](ncols)
@@ -306,7 +316,7 @@ object JdbcUtils extends Logging with SQLConfHelper {
 
       val columnType =
         dialect.getCatalystType(dataType, typeName, fieldSize, metadata).getOrElse(
-          getCatalystType(dataType, fieldSize, fieldScale, isSigned))
+          getCatalystType(dataType, fieldSize, fieldScale, isSigned, isTimestampNTZ))
       fields(i) = StructField(columnName, columnType, nullable, metadata.build())
       i = i + 1
     }
@@ -463,7 +473,7 @@ object JdbcUtils extends Logging with SQLConfHelper {
         }
       }
 
-    case TimestampType =>
+    case TimestampType | TimestampNTZType =>
       (rs: ResultSet, row: InternalRow, pos: Int) =>
         val t = rs.getTimestamp(pos + 1)
         if (t != null) {
@@ -583,6 +593,18 @@ object JdbcUtils extends Logging with SQLConfHelper {
           stmt.setTimestamp(pos + 1, row.getAs[java.sql.Timestamp](pos))
       }
 
+    case TimestampNTZType =>
+      if (conf.datetimeJava8ApiEnabled) {
+        (stmt: PreparedStatement, row: Row, pos: Int) =>
+          stmt.setTimestamp(pos + 1, toJavaTimestamp(instantToMicros(row.getAs[Instant](pos))))
+      } else {
+        (stmt: PreparedStatement, row: Row, pos: Int) =>
+          stmt.setTimestamp(
+            pos + 1,
+            toJavaTimestamp(localDateTimeToMicros(row.getAs[java.time.LocalDateTime](pos)))
+          )
+      }
+
     case DateType =>
       if (conf.datetimeJava8ApiEnabled) {
         (stmt: PreparedStatement, row: Row, pos: Int) =>

sql/core/src/main/scala/org/apache/spark/sql/jdbc/MsSqlServerDialect.scala

@@ -98,6 +98,7 @@ private object MsSqlServerDialect extends JdbcDialect {
 
   override def getJDBCType(dt: DataType): Option[JdbcType] = dt match {
     case TimestampType => Some(JdbcType("DATETIME", java.sql.Types.TIMESTAMP))
+    case TimestampNTZType => Some(JdbcType("DATETIME", java.sql.Types.TIMESTAMP))
     case StringType => Some(JdbcType("NVARCHAR(MAX)", java.sql.Types.NVARCHAR))
     case BooleanType => Some(JdbcType("BIT", java.sql.Types.BIT))
     case BinaryType => Some(JdbcType("VARBINARY(MAX)", java.sql.Types.VARBINARY))

sql/core/src/test/scala/org/apache/spark/sql/jdbc/JDBCSuite.scala

@@ -19,7 +19,7 @@ package org.apache.spark.sql.jdbc
 
 import java.math.BigDecimal
 import java.sql.{Date, DriverManager, SQLException, Timestamp}
-import java.time.{Instant, LocalDate}
+import java.time.{Instant, LocalDate, LocalDateTime}
 import java.util.{Calendar, GregorianCalendar, Properties, TimeZone}
 
 import scala.collection.JavaConverters._
@@ -1230,6 +1230,7 @@ class JDBCSuite extends QueryTest
     assert(getJdbcType(oracleDialect, BinaryType) == "BLOB")
     assert(getJdbcType(oracleDialect, DateType) == "DATE")
     assert(getJdbcType(oracleDialect, TimestampType) == "TIMESTAMP")
+    assert(getJdbcType(oracleDialect, TimestampNTZType) == "TIMESTAMP")
   }
 
   private def assertEmptyQuery(sqlString: String): Unit = {
@@ -1879,5 +1880,53 @@ class JDBCSuite extends QueryTest
     val fields = schema.fields
     assert(fields.length === 1)
     assert(fields(0).dataType === StringType)
-   }
+  }
+
+  test("SPARK-39339: Handle TimestampNTZType null values") {
+    val tableName = "timestamp_ntz_null_table"
+
+    val df = Seq(null.asInstanceOf[LocalDateTime]).toDF("col1")
+
+    df.write.format("jdbc")
+      .option("url", urlWithUserAndPass)
+      .option("dbtable", tableName).save()
+
+    val res = spark.read.format("jdbc")
+      .option("inferTimestampNTZType", "true")
+      .option("url", urlWithUserAndPass)
+      .option("dbtable", tableName)
+      .load()
+
+    checkAnswer(res, Seq(Row(null)))
+  }
+
+  test("SPARK-39339: TimestampNTZType with different local time zones") {
+    val tableName = "timestamp_ntz_diff_tz_support_table"
+
+    DateTimeTestUtils.outstandingTimezonesIds.foreach { timeZone =>
+      withSQLConf(SQLConf.SESSION_LOCAL_TIMEZONE.key -> timeZone) {
+        Seq(
+          "1972-07-04 03:30:00",
+          "2019-01-20 12:00:00.502",
+          "2019-01-20T00:00:00.123456",
+          "1500-01-20T00:00:00.123456"
+        ).foreach { case datetime =>
+          val df = spark.sql(s"select timestamp_ntz '$datetime'")
+          df.write.format("jdbc")
+            .mode("overwrite")
+            .option("url", urlWithUserAndPass)
+            .option("dbtable", tableName)
+            .save()
+
+          val res = spark.read.format("jdbc")
+            .option("inferTimestampNTZType", "true")
+            .option("url", urlWithUserAndPass)
+            .option("dbtable", tableName)
+            .load()
+
+          checkAnswer(res, df)
+        }
+      }
+    }
+  }
 }