Throw exception when use non existing database.

Author: viirya

sql/core/src/main/scala/org/apache/spark/sql/execution/commands.scala

@@ -413,8 +413,13 @@ case class SetDatabaseCommand(databaseName: String) extends RunnableCommand {
 
   override def run(sqlContext: SQLContext): Seq[Row] = {
     sqlContext.catalog.setCurrentDatabase(databaseName)
-    Seq.empty[Row]
+    Seq(Row("OK"))
   }
 
-  override def output: Seq[Attribute] = Seq.empty
+  override val output: Seq[Attribute] = {
+    val schema = StructType(
+      StructField("output", StringType, nullable = false) :: Nil)
+
+    schema.toAttributes
+  }
 }

sql/hive/src/main/scala/org/apache/spark/sql/hive/client/ClientWrapper.scala

@@ -35,6 +35,7 @@ import org.apache.hadoop.hive.shims.{HadoopShims, ShimLoader}
 import org.apache.hadoop.security.UserGroupInformation
 
 import org.apache.spark.{Logging, SparkConf, SparkException}
+import org.apache.spark.sql.catalyst.analysis.NoSuchDatabaseException
 import org.apache.spark.sql.catalyst.expressions.Expression
 import org.apache.spark.sql.execution.QueryExecutionException
 import org.apache.spark.util.{CircularBuffer, Utils}
@@ -230,7 +231,11 @@ private[hive] class ClientWrapper(
   }
 
   override def setCurrentDatabase(databaseName: String): Unit = withHiveState {
-    state.setCurrentDatabase(databaseName)
+    if (getDatabaseOption(databaseName).isDefined) {
+      state.setCurrentDatabase(databaseName)
+    } else {
+      throw new NoSuchDatabaseException
+    }
   }
 
   override def createDatabase(database: HiveDatabase): Unit = withHiveState {

sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveQuerySuite.scala

@@ -29,6 +29,7 @@ import org.scalatest.BeforeAndAfter
 import org.apache.spark.{SparkException, SparkFiles}
 import org.apache.spark.sql.{AnalysisException, DataFrame, Row}
 import org.apache.spark.sql.catalyst.expressions.Cast
+import org.apache.spark.sql.catalyst.analysis.NoSuchDatabaseException
 import org.apache.spark.sql.catalyst.plans.logical.Project
 import org.apache.spark.sql.execution.joins.BroadcastNestedLoopJoin
 import org.apache.spark.sql.hive._
@@ -1264,13 +1265,15 @@ class HiveQuerySuite extends HiveComparisonTest with BeforeAndAfter {
 
   test("use database") {
     val currentDatabase = sql("select current_database()").first().getString(0)
-    sql("USE test")
-    assert("test" == sql("select current_database()").first().getString(0))
 
     sql("CREATE DATABASE hive_test_db")
     sql("USE hive_test_db")
     assert("hive_test_db" == sql("select current_database()").first().getString(0))
 
+    intercept[NoSuchDatabaseException] {
+      sql("USE not_existing_db")
+    }
+
     sql(s"USE $currentDatabase")
     assert(currentDatabase == sql("select current_database()").first().getString(0))
   }