Added semantic error for HAVING without GROUP BY

Author: willb

sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveQl.scala

@@ -204,6 +204,9 @@ private[hive] object HiveQl {
   class ParseException(sql: String, cause: Throwable)
     extends Exception(s"Failed to parse: $sql", cause)
 
+  class SemanticException(msg: String)
+    extends Exception(msg)
+
   /**
    * Returns the AST for the given SQL string.
    */
@@ -579,6 +582,11 @@ private[hive] object HiveQl {
           if (selectDistinctClause.isDefined) Distinct(withProject) else withProject
 
         val withHaving = havingClause.map { h => 
+
+          if (groupByClause == None) {
+            throw new SemanticException("Error in semantic analysis: HAVING specified without GROUP BY")
+          }
+
           val Seq(havingExpr) = h.getChildren.toSeq
           Filter(nodeToExpr(havingExpr), withDistinct)
         }.getOrElse(withDistinct)