[SPARK-16515][SQL] set default record reader and writer for script transformation

## What changes were proposed in this pull request?
In ScriptInputOutputSchema, we read default RecordReader and RecordWriter from conf. Since Spark 2.0 has deleted those config keys from hive conf, we have to set default reader/writer class name by ourselves. Otherwise we will get None for LazySimpleSerde, the data written would not be able to read by script. The test case added worked fine with previous version of Spark, but would fail now.

## How was this patch tested?
added a test case in SQLQuerySuite.

Closes #14169

Author: Daoyuan Wang <daoyuan.wang@intel.com>
Author: Yin Huai <yhuai@databricks.com>

Closes #14249 from yhuai/scriptTransformation.

1 files changed, 11 insertions, 0 deletions

diff --git a/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/SQLQuerySuite.scala b/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/SQLQuerySuite.scala
index 961d95c268..cb8f79982b 100644
--- a/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/SQLQuerySuite.scala
+++ b/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/SQLQuerySuite.scala
@@ -63,6 +63,17 @@ class SQLQuerySuite extends QueryTest with SQLTestUtils with TestHiveSingleton {
   import hiveContext._
   import spark.implicits._
 
+  test("script") {
+    val df = Seq(("x1", "y1", "z1"), ("x2", "y2", "z2")).toDF("c1", "c2", "c3")
+    df.createOrReplaceTempView("script_table")
+    val query1 = sql(
+      """
+        |SELECT col1 FROM (from(SELECT c1, c2, c3 FROM script_table) tempt_table
+        |REDUCE c1, c2, c3 USING 'bash src/test/resources/test_script.sh' AS
+        |(col1 STRING, col2 STRING)) script_test_table""".stripMargin)
+    checkAnswer(query1, Row("x1_y1") :: Row("x2_y2") :: Nil)
+  }
+
   test("UDTF") {
     withUserDefinedFunction("udtf_count2" -> true) {
       sql(s"ADD JAR ${hiveContext.getHiveFile("TestUDTF.jar").getCanonicalPath()}")