[SPARK-5002][SQL] Using ascending by default when not specify order in order by

spark sql does not support ```SELECT a, b FROM testData2 ORDER BY a desc, b```.

Author: wangfei <wangfei1@huawei.com>

Closes #3838 from scwf/orderby and squashes the following commits:

114b64a [wangfei] remove nouse methods
48145d3 [wangfei] fix order, using asc by default

1 files changed, 2 insertions, 6 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 d4fc9bbfd3..66860a4c09 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
@@ -209,15 +209,11 @@ class SqlParser extends AbstractSparkSQLParser {
     )
 
   protected lazy val ordering: Parser[Seq[SortOrder]] =
-    ( rep1sep(singleOrder, ",")
-    | rep1sep(expression, ",") ~ direction.? ^^ {
-        case exps ~ d => exps.map(SortOrder(_, d.getOrElse(Ascending)))
+    ( rep1sep(expression ~ direction.? , ",") ^^ {
+        case exps  => exps.map(pair => SortOrder(pair._1, pair._2.getOrElse(Ascending)))
       }
     )
 
-  protected lazy val singleOrder: Parser[SortOrder] =
-    expression ~ direction ^^ { case e ~ o => SortOrder(e, o) }
-
   protected lazy val direction: Parser[SortDirection] =
     ( ASC  ^^^ Ascending
     | DESC ^^^ Descending