Merge pull request #620 from stumc/Issue#619

Issue#619 CTE have wrong column names when AS newname used with simpl…

h2/src/main/org/h2/command/Parser.java

@@ -5032,10 +5032,20 @@ public class Parser {
             querySQL = StringUtils.cache(withQuery.getPlanSQL());
             ArrayList<Expression> withExpressions = withQuery.getExpressions();
             for (int i = 0; i < withExpressions.size(); ++i) {
-                String columnName = cols != null ? cols[i]
-                        : withExpressions.get(i).getColumnName();
+                Expression columnExp = withExpressions.get(i);
+                // use the passed in column name if supplied, otherwise use alias (if used) otherwise use column name
+                // derived from column expression
+                String columnName;
+                if (cols != null){
+                    columnName = cols[i];
+                } else if (columnExp.getAlias()!=null){
+                    columnName = columnExp.getAlias();
+                }
+                else{
+                     columnName =  columnExp.getColumnName();
+                }
                 columnTemplateList.add(new Column(columnName,
-                        withExpressions.get(i).getType()));
+                        columnExp.getType()));
             }
         } finally {
             session.removeLocalTempTable(recursiveTable);

h2/src/test/org/h2/test/db/TestGeneralCommonTableQueries.java

@@ -34,6 +34,7 @@ public class TestGeneralCommonTableQueries extends TestBase {
         testChainedQuery();
         testParameterizedQuery();
         testNumberedParameterizedQuery();
+        testColumnNames();
 
         testInsert();
         testUpdate();
@@ -438,4 +439,34 @@ public class TestGeneralCommonTableQueries extends TestBase {
         conn.close();
         deleteDb("commonTableExpressionQueries");
     }    
+
+    private void testColumnNames() throws Exception {
+        deleteDb("commonTableExpressionQueries");
+        Connection conn = getConnection("commonTableExpressionQueries");
+        PreparedStatement prep;
+        ResultSet rs;
+
+        conn.setAutoCommit(false);
+
+        prep = conn.prepareStatement("WITH t1 AS ("
+            +"     SELECT 1 AS ONE, R.X AS TWO, 'T1' AS THREE, X FROM SYSTEM_RANGE(1,1) R"
+            +")"
+            +"SELECT * FROM t1");
+        rs = prep.executeQuery();
+
+        for (int n : new int[] { 1 }) {
+            assertTrue(rs.next());
+            assertEquals(n, rs.getInt(1));
+            assertEquals(n, rs.getInt(4));
+        }
+        assertEquals("ONE",rs.getMetaData().getColumnLabel(1));
+        assertEquals("TWO",rs.getMetaData().getColumnLabel(2));
+        assertEquals("THREE",rs.getMetaData().getColumnLabel(3));
+        assertEquals("X",rs.getMetaData().getColumnLabel(4));
+
+        assertFalse(rs.next());
+
+        conn.close();
+        deleteDb("commonTableExpressionQueries");
+    }
 }
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