[SPARK-5029][SQL] Enable from follow multiple brackets

Enable from follow multiple brackets:
```
select key from ((select * from testData limit 1) union all (select * from testData limit 1)) x limit 1
```

Author: scwf <wangfei1@huawei.com>

Closes #3853 from scwf/from and squashes the following commits:

14f110a [scwf] enable from follow multiple brackets

1 files changed, 1 insertions, 1 deletions

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/SqlParser.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/SqlParser.scala
index fc7b874559..5d974df98b 100755
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/SqlParser.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/SqlParser.scala
@@ -125,7 +125,7 @@ class SqlParser extends AbstractSparkSQLParser {
   }
 
   protected lazy val start: Parser[LogicalPlan] =
-    ( select *
+    ( (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)}