[SPARK-9295] Analysis should detect sorting on unsupported column types

This patch extends CheckAnalysis to throw errors for queries that try to sort on unsupported column types, such as ArrayType.

Author: Josh Rosen <joshrosen@databricks.com>

Closes #7633 from JoshRosen/SPARK-9295 and squashes the following commits:

23b2fbf [Josh Rosen] Embed function in foreach
bfe1451 [Josh Rosen] Update to allow sorting by null literals
2f1b802 [Josh Rosen] Add analysis rule to detect sorting on unsupported column types (SPARK-9295)

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/CheckAnalysis.scala

@@ -103,6 +103,16 @@ trait CheckAnalysis {
 
             aggregateExprs.foreach(checkValidAggregateExpression)
 
+          case Sort(orders, _, _) =>
+            orders.foreach { order =>
+              order.dataType match {
+                case t: AtomicType => // OK
+                case NullType => // OK
+                case t =>
+                  failAnalysis(s"Sorting is not supported for columns of type ${t.simpleString}")
+              }
+            }
+
           case _ => // Fallbacks to the following checks
         }
 

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/analysis/AnalysisErrorSuite.scala

@@ -113,6 +113,11 @@ class AnalysisErrorSuite extends SparkFunSuite with BeforeAndAfter {
     testRelation.select(Literal(1).cast(BinaryType).as('badCast)),
     "cannot cast" :: Literal(1).dataType.simpleString :: BinaryType.simpleString :: Nil)
 
+  errorTest(
+    "sorting by unsupported column types",
+    listRelation.orderBy('list.asc),
+    "sorting" :: "type" :: "array<int>" :: Nil)
+
   errorTest(
     "non-boolean filters",
     testRelation.where(Literal(1)),