[SPARK-6871][SQL] WITH clause in CTE can not following another WITH clause

JIRA https://issues.apache.org/jira/browse/SPARK-6871

Author: Liang-Chi Hsieh <[email protected]>

Closes apache#5480 from viirya/no_cte_after_cte and squashes the following commits:

4da3712 [Liang-Chi Hsieh] Create new test.
40b38ed [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into no_cte_after_cte
0edf568 [Liang-Chi Hsieh] for comments.
6591b79 [Liang-Chi Hsieh] WITH clause in CTE can not following another WITH clause.

Author: viirya

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/SqlParser.scala

@@ -121,14 +121,14 @@ class SqlParser extends AbstractSparkSQLParser with DataTypeParser {
   }
 
   protected lazy val start: Parser[LogicalPlan] =
-    ( (select | ("(" ~> select <~ ")")) *
-      ( UNION ~ ALL        ^^^ { (q1: LogicalPlan, q2: LogicalPlan) => Union(q1, q2) }
-      | INTERSECT          ^^^ { (q1: LogicalPlan, q2: LogicalPlan) => Intersect(q1, q2) }
-      | EXCEPT             ^^^ { (q1: LogicalPlan, q2: LogicalPlan) => Except(q1, q2)}
-      | UNION ~ DISTINCT.? ^^^ { (q1: LogicalPlan, q2: LogicalPlan) => Distinct(Union(q1, q2)) }
-      )
-    | insert
-    | cte
+    start1 | insert | cte
+
+  protected lazy val start1: Parser[LogicalPlan] =
+    (select | ("(" ~> select <~ ")")) *
+    ( UNION ~ ALL        ^^^ { (q1: LogicalPlan, q2: LogicalPlan) => Union(q1, q2) }
+    | INTERSECT          ^^^ { (q1: LogicalPlan, q2: LogicalPlan) => Intersect(q1, q2) }
+    | EXCEPT             ^^^ { (q1: LogicalPlan, q2: LogicalPlan) => Except(q1, q2)}
+    | UNION ~ DISTINCT.? ^^^ { (q1: LogicalPlan, q2: LogicalPlan) => Distinct(Union(q1, q2)) }
     )
 
   protected lazy val select: Parser[LogicalPlan] =
@@ -159,7 +159,7 @@ class SqlParser extends AbstractSparkSQLParser with DataTypeParser {
     }
 
   protected lazy val cte: Parser[LogicalPlan] =
-    WITH ~> rep1sep(ident ~ ( AS ~ "(" ~> start <~ ")"), ",") ~ start ^^ {
+    WITH ~> rep1sep(ident ~ ( AS ~ "(" ~> start1 <~ ")"), ",") ~ (start1 | insert) ^^ {
       case r ~ s => With(s, r.map({case n ~ s => (n, Subquery(n, s))}).toMap)
     }
 

sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala

@@ -431,6 +431,12 @@ class SQLQuerySuite extends QueryTest with BeforeAndAfterAll {
 
   }
 
+  test("Allow only a single WITH clause per query") {
+    intercept[RuntimeException] {
+      sql("with q1 as (select * from testData) with q2 as (select * from q1) select * from q2")
+    }
+  }
+
   test("date row") {
     checkAnswer(sql(
       """select cast("2015-01-28" as date) from testData limit 1"""),