[SPARK-6145][SQL] fix ORDER BY on nested fields

Based on #4904 with style errors fixed.

`LogicalPlan#resolve` will not only produce `Attribute`, but also "`GetField` chain".
So in `ResolveSortReferences`, after resolve the ordering expressions, we should not just collect the `Attribute` results, but also `Attribute` at the bottom of "`GetField` chain".

Author: Wenchen Fan <cloud0fan@outlook.com>
Author: Michael Armbrust <michael@databricks.com>

Closes #4918 from marmbrus/pr/4904 and squashes the following commits:

997f84e [Michael Armbrust] fix style
3eedbfc [Wenchen Fan] fix 6145

1 files changed, 10 insertions, 0 deletions

diff --git a/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala
index 097bf0dd23..4dedcd365f 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala
@@ -1049,4 +1049,14 @@ class SQLQuerySuite extends QueryTest with BeforeAndAfterAll {
     rdd.toDF().registerTempTable("distinctData")
     checkAnswer(sql("SELECT COUNT(DISTINCT key,value) FROM distinctData"), Row(2))
   }
+
+  test("SPARK-6145: ORDER BY test for nested fields") {
+    jsonRDD(sparkContext.makeRDD(
+      """{"a": {"b": 1, "a": {"a": 1}}, "c": [{"d": 1}]}""" :: Nil)).registerTempTable("nestedOrder")
+    // These should be successfully analyzed
+    sql("SELECT 1 FROM nestedOrder ORDER BY a.b").queryExecution.analyzed
+    sql("SELECT a.b FROM nestedOrder ORDER BY a.b").queryExecution.analyzed
+    sql("SELECT 1 FROM nestedOrder ORDER BY a.a.a").queryExecution.analyzed
+    sql("SELECT 1 FROM nestedOrder ORDER BY c[0].d").queryExecution.analyzed
+  }
 }