[SPARK-50215][SQL] Refactored StringType pattern matching in jdbc cod…

…e stack

### What changes were proposed in this pull request?

I propose chaning pattern matching of `StringType` in the `jdbc` code stack.

### Why are the changes needed?

These changes are needed in order to properly handle collated `StringType` in the `jdbc` code stack.

### Does this PR introduce _any_ user-facing change?

No.

### How was this patch tested?

No testing was needed.

### Was this patch authored or co-authored using generative AI tooling?

No.

Closes #48749 from vladanvasi-db/vladanvasi-db/jdbc-stringtype-match-refactor.

Authored-by: Vladan Vasić <[email protected]>
Signed-off-by: Max Gekk <[email protected]>

sql/core/src/main/scala/org/apache/spark/sql/jdbc/DB2Dialect.scala

@@ -101,7 +101,7 @@ private case class DB2Dialect() extends JdbcDialect with SQLConfHelper with NoLe
   }
 
   override def getJDBCType(dt: DataType): Option[JdbcType] = dt match {
-    case StringType => Option(JdbcType("CLOB", java.sql.Types.CLOB))
+    case _: StringType => Option(JdbcType("CLOB", java.sql.Types.CLOB))
     case BooleanType if conf.legacyDB2BooleanMappingEnabled =>
       Option(JdbcType("CHAR(1)", java.sql.Types.CHAR))
     case BooleanType => Option(JdbcType("BOOLEAN", java.sql.Types.BOOLEAN))

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

@@ -44,7 +44,7 @@ private case class DatabricksDialect() extends JdbcDialect with NoLegacyJDBCErro
   override def getJDBCType(dt: DataType): Option[JdbcType] = dt match {
     case BooleanType => Some(JdbcType("BOOLEAN", java.sql.Types.BOOLEAN))
     case DoubleType => Some(JdbcType("DOUBLE", java.sql.Types.DOUBLE))
-    case StringType => Some(JdbcType("STRING", java.sql.Types.VARCHAR))
+    case _: StringType => Some(JdbcType("STRING", java.sql.Types.VARCHAR))
     case BinaryType => Some(JdbcType("BINARY", java.sql.Types.BINARY))
     case _ => None
   }

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

@@ -44,7 +44,7 @@ private case class DerbyDialect() extends JdbcDialect with NoLegacyJDBCError {
   }
 
   override def getJDBCType(dt: DataType): Option[JdbcType] = dt match {
-    case StringType => Option(JdbcType("CLOB", java.sql.Types.CLOB))
+    case _: StringType => Option(JdbcType("CLOB", java.sql.Types.CLOB))
     case ByteType => Option(JdbcType("SMALLINT", java.sql.Types.SMALLINT))
     case ShortType => Option(JdbcType("SMALLINT", java.sql.Types.SMALLINT))
     case BooleanType => Option(JdbcType("BOOLEAN", java.sql.Types.BOOLEAN))

sql/core/src/main/scala/org/apache/spark/sql/jdbc/H2Dialect.scala

@@ -73,7 +73,7 @@ private[sql] case class H2Dialect() extends JdbcDialect with NoLegacyJDBCError {
   }
 
   override def getJDBCType(dt: DataType): Option[JdbcType] = dt match {
-    case StringType => Option(JdbcType("CLOB", Types.CLOB))
+    case _: StringType => Option(JdbcType("CLOB", Types.CLOB))
     case BooleanType => Some(JdbcType("BOOLEAN", Types.BOOLEAN))
     case ShortType | ByteType => Some(JdbcType("SMALLINT", Types.SMALLINT))
     case t: DecimalType => Some(

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

@@ -135,7 +135,7 @@ private case class MsSqlServerDialect() extends JdbcDialect with NoLegacyJDBCErr
   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 _: 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))
     case ShortType if !SQLConf.get.legacyMsSqlServerNumericMappingEnabled =>

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

@@ -256,7 +256,7 @@ private case class MySQLDialect() extends JdbcDialect with SQLConfHelper with No
     // See SPARK-35446: MySQL treats REAL as a synonym to DOUBLE by default
     // We override getJDBCType so that FloatType is mapped to FLOAT instead
     case FloatType => Option(JdbcType("FLOAT", java.sql.Types.FLOAT))
-    case StringType => Option(JdbcType("LONGTEXT", java.sql.Types.LONGVARCHAR))
+    case _: StringType => Option(JdbcType("LONGTEXT", java.sql.Types.LONGVARCHAR))
     case ByteType => Option(JdbcType("TINYINT", java.sql.Types.TINYINT))
     case ShortType => Option(JdbcType("SMALLINT", java.sql.Types.SMALLINT))
     // scalastyle:off line.size.limit

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

@@ -121,7 +121,7 @@ private case class OracleDialect() extends JdbcDialect with SQLConfHelper with N
     case DoubleType => Some(JdbcType("NUMBER(19, 4)", java.sql.Types.DOUBLE))
     case ByteType => Some(JdbcType("NUMBER(3)", java.sql.Types.SMALLINT))
     case ShortType => Some(JdbcType("NUMBER(5)", java.sql.Types.SMALLINT))
-    case StringType => Some(JdbcType("VARCHAR2(255)", java.sql.Types.VARCHAR))
+    case _: StringType => Some(JdbcType("VARCHAR2(255)", java.sql.Types.VARCHAR))
     case VarcharType(n) => Some(JdbcType(s"VARCHAR2($n)", java.sql.Types.VARCHAR))
     case TimestampType if !conf.legacyOracleTimestampMappingEnabled =>
       Some(JdbcType("TIMESTAMP WITH LOCAL TIME ZONE", TIMESTAMP_LTZ))

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

@@ -145,7 +145,7 @@ private case class PostgresDialect()
   }
 
   override def getJDBCType(dt: DataType): Option[JdbcType] = dt match {
-    case StringType => Some(JdbcType("TEXT", Types.VARCHAR))
+    case _: StringType => Some(JdbcType("TEXT", Types.VARCHAR))
     case BinaryType => Some(JdbcType("BYTEA", Types.BINARY))
     case BooleanType => Some(JdbcType("BOOLEAN", Types.BOOLEAN))
     case FloatType => Some(JdbcType("FLOAT4", Types.FLOAT))

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

@@ -40,7 +40,7 @@ private case class TeradataDialect() extends JdbcDialect with NoLegacyJDBCError
     supportedFunctions.contains(funcName)
 
   override def getJDBCType(dt: DataType): Option[JdbcType] = dt match {
-    case StringType => Some(JdbcType("VARCHAR(255)", java.sql.Types.VARCHAR))
+    case _: StringType => Some(JdbcType("VARCHAR(255)", java.sql.Types.VARCHAR))
     case BooleanType => Option(JdbcType("CHAR(1)", java.sql.Types.CHAR))
     case ByteType => Option(JdbcType("BYTEINT", java.sql.Types.TINYINT))
     case _ => None