Author: kmarsden
Date: Tue Nov  4 09:19:03 2008
New Revision: 711321

URL: http://svn.apache.org/viewvc?rev=711321&view=rev
Log:
DERBY-3880 NPE on a query with having clause involving a join

remap expression for AggregateNode operand if the JoinNode has been flattened.

Fix contributed by Army Brown

Modified:
    db/derby/code/trunk/java/engine/org/apache/derby/impl/sql/compile/AggregateNode.java
    db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/lang/GroupByTest.java

Modified: db/derby/code/trunk/java/engine/org/apache/derby/impl/sql/compile/AggregateNode.java
URL: http://svn.apache.org/viewvc/db/derby/code/trunk/java/engine/org/apache/derby/impl/sql/compile/AggregateNode.java?rev=711321&r1=711320&r2=711321&view=diff
==============================================================================
--- db/derby/code/trunk/java/engine/org/apache/derby/impl/sql/compile/AggregateNode.java (original)
+++ db/derby/code/trunk/java/engine/org/apache/derby/impl/sql/compile/AggregateNode.java Tue Nov  4 09:19:03 2008
@@ -539,6 +539,27 @@
 			this.getNewNullResultExpression() :
 			operand;
 
+
+		/* The operand for this aggregate node was initialized at bind
+		 * time. Between then and now it's possible that certain changes
+		 * have been made to the query tree which affect this operand. In
+		 * particular, if the operand was pointing to a result column in
+		 * a JoinNode and then that JoinNode was flattened during pre-
+		 * processing, all of the references to that JoinNode--including
+		 * this aggregate's operand--need to be updated to reflect the
+		 * fact that the Join Node no longer exists. So check to see if
+		 * the operand is a column reference, and if so, make a call to
+		 * remap it to its underlying expression. If nothing has happened
+		 * then this will be a no-op; but if something has changed to void
+		 * out the result column to which the operand points, the result
+		 * column will be marked "redundant" and the following call should
+		 * remap as appropriate. DERBY-3880.
+		 */
+		if (operand instanceof ColumnReference)
+		{
+			((ColumnReference)operand).remapColumnReferencesToExpressions();
+		}
+
 		return (ResultColumn) getNodeFactory().getNode(
 								C_NodeTypes.RESULT_COLUMN,
 								"##aggregate expression",

Modified: db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/lang/GroupByTest.java
URL: http://svn.apache.org/viewvc/db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/lang/GroupByTest.java?rev=711321&r1=711320&r2=711321&view=diff
==============================================================================
--- db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/lang/GroupByTest.java (original)
+++ db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/lang/GroupByTest.java Tue Nov  4 09:19:03 2008
@@ -276,6 +276,16 @@
 
       st.executeUpdate(
     		  "insert into EMPTAB values( 1, 1000, 1 )"); 
+	
+      // tables for DERBY-3880 testing
+      st.executeUpdate("CREATE TABLE T1_D3880(i int, c varchar(20))");
+      st.executeUpdate("create table t2_D3880(i int, c2 varchar(20), i2 int)");
+      st.executeUpdate("insert into t1_D3880 values(1, 'abc')");
+      st.executeUpdate("insert into t1_D3880 values(2, 'abc')");
+      st.executeUpdate("insert into t2_D3880 values(1, 'xyz', 10)");
+      st.executeUpdate("insert into t2_D3880 values(1, 'aaa', 20)");
+      st.executeUpdate("insert into t2_D3880 values(2, 'xxx', 30)");
+      
 	}
 
 	/**
@@ -1446,6 +1456,16 @@
 		JDBC.assertEmpty(s.executeQuery("select orderID from session.ztemp group by orderID"));
 	}
 
+	public void testHavingWithInnerJoinDerby3880() throws SQLException {
+		Statement s = createStatement();
+		ResultSet rs = s.executeQuery("select   t1_D3880.i, avg(t2_D3880.i2)  from t1_D3880 " +
+				"inner join t2_D3880 on (t1_D3880.i = t2_D3880.i) group by t1_D3880.i having "  +
+						"avg(t2_D3880.i2) > 0");
+		String[][] expRs = new String[][] {{"1","15"},{"2","30"}};
+		JDBC.assertFullResultSet(rs,expRs);
+
+	}
+	
 	/**
 	 * DERBY-280: Wrong result from select when aliasing to same name as used
 	 * in group by