[SPARK-11394][SQL] Throw IllegalArgumentException for unsupported types in postgresql

If DataFrame has BYTE types, throws an exception:
org.postgresql.util.PSQLException: ERROR: type "byte" does not exist

Author: Takeshi YAMAMURO <linguin.m.s@gmail.com>

Closes #9350 from maropu/FixBugInPostgreJdbc.

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

@@ -64,6 +64,7 @@ private object PostgresDialect extends JdbcDialect {
       getJDBCType(et).map(_.databaseTypeDefinition)
         .orElse(JdbcUtils.getCommonJDBCType(et).map(_.databaseTypeDefinition))
         .map(typeName => JdbcType(s"$typeName[]", java.sql.Types.ARRAY))
+    case ByteType => throw new IllegalArgumentException(s"Unsupported type in postgresql: $dt");
     case _ => None
   }
 

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

@@ -482,6 +482,10 @@ class JDBCSuite extends SparkFunSuite
     val Postgres = JdbcDialects.get("jdbc:postgresql://127.0.0.1/db")
     assert(Postgres.getCatalystType(java.sql.Types.OTHER, "json", 1, null) === Some(StringType))
     assert(Postgres.getCatalystType(java.sql.Types.OTHER, "jsonb", 1, null) === Some(StringType))
+    val errMsg = intercept[IllegalArgumentException] {
+      Postgres.getJDBCType(ByteType)
+    }
+    assert(errMsg.getMessage contains "Unsupported type in postgresql: ByteType")
   }
 
   test("DerbyDialect jdbc type mapping") {