Refined extra error messages

h2/src/docsrc/help/help.csv

@@ -124,10 +124,10 @@ MERGE INTO TEST KEY(ID) VALUES(2, 'World')
 
 "Commands (DML)","MERGE USING","
 MERGE INTO targetTableName [ [AS] targetAlias] 
-USING { ( select ) | sourceTableName }[ [AS] sourceAlias ]
-ON ( expression ) 
-[ WHEN MATCHED THEN [ update ] [ delete] ]
-[ WHEN NOT MATCHED THEN insert  ]
+ USING { ( select ) | sourceTableName }[ [AS] sourceAlias ]
+ ON ( expression ) 
+ [ WHEN MATCHED THEN [ update ] [ delete] ]
+ [ WHEN NOT MATCHED THEN insert  ]
 ","
 Updates or deletes existing rows, and insert rows that don't exist. The ON clause 
 specifies the matching column expression and must be specified. If more than one row 

h2/src/main/org/h2/command/dml/MergeUsing.java

@@ -106,7 +106,7 @@ public class MergeUsing extends Merge {
                 }
             }
             if(sourceKeysRemembered.containsKey(sourceKeyValuesList)){
-                throw DbException.get(ErrorCode.DUPLICATE_KEY_1, "Merge using ON column expression, duplicate values found:keys"
+                throw DbException.get(ErrorCode.DUPLICATE_KEY_1, "Merge using ON column expression, duplicate values found:key columns"
                         +Arrays.asList(sourceKeys).toString()+":values:"+sourceKeyValuesList.toString()
                         +":from:"+sourceTableFilter.getTable()+":alias:"+sourceTableFilter.getTableAlias()+":current row number:"+countInputRows
                         +":conflicting row number:"+sourceKeysRemembered.get(sourceKeyValuesList));
@@ -174,7 +174,7 @@ public class MergeUsing extends Merge {
             rowUpdateCount += updateCommand.update();
             System.out.println("update.count="+rowUpdateCount);
         }
-        if(deleteCommand!=null && rowUpdateCount==0){
+        if(deleteCommand!=null){
             System.out.println("deleteCommand="+deleteCommand.getPlanSQL());
             rowUpdateCount += deleteCommand.update();
             System.out.println("delete.count="+rowUpdateCount);
@@ -364,11 +364,19 @@ public class MergeUsing extends Merge {
         
         if (keys == null) {
             HashSet<Column> targetColumns = buildColumnListFromOnCondition(targetTableFilter);
-            keys = targetColumns.toArray(new Column[1]);
+            keys = targetColumns.toArray(new Column[0]);
+            System.out.println("keys.length="+keys.length);
+        }     
+        if(keys.length==0){
+            throw DbException.get(ErrorCode.COLUMN_NOT_FOUND_1,"No references to target columns found in ON clause:"+targetTableFilter.toString());
         }
         if (sourceKeys == null) {
             HashSet<Column> sourceColumns = buildColumnListFromOnCondition(sourceTableFilter);
-            sourceKeys = sourceColumns.toArray(new Column[1]);
+            sourceKeys = sourceColumns.toArray(new Column[0]);
+            System.out.println("sourceKeys.length="+sourceKeys.length);
+        }       
+        if(sourceKeys.length==0){
+            throw DbException.get(ErrorCode.COLUMN_NOT_FOUND_1,"No references to source columns found in ON clause:"+sourceTableFilter.toString());
         }
         
         // only do the optimise now - before we have already gathered the unoptimized column data
@@ -434,21 +442,19 @@ public class MergeUsing extends Merge {
     }
 
 
-    private HashSet<Column> buildColumnListFromOnCondition(TableFilter targetTableFilter) {
-        HashSet<Column> targetColumns = new HashSet<Column>();
+    private HashSet<Column> buildColumnListFromOnCondition(TableFilter anyTableFilter) {
+        HashSet<Column> filteredColumns = new HashSet<Column>();
         HashSet<Column> columns = new HashSet<Column>();
         ExpressionVisitor visitor = ExpressionVisitor.getColumnsVisitor(columns);
         onCondition.isEverything(visitor);
         for(Column c: columns){
-            if(c.getTable()==targetTableFilter.getTable()){
-                targetColumns.add(c);
-            }
+            System.out.println("C="+c);
+            if(c!=null && c.getTable()==anyTableFilter.getTable()){
+                filteredColumns.add(c);
             }
-        System.out.println("columnsVisitedForTable"+targetTableFilter.getTable()+"="+targetColumns);
-        if (targetColumns.isEmpty()) {
-            throw DbException.get(ErrorCode.CONSTRAINT_NOT_FOUND_1, "ON (condition) target columns missing");
         }
-        return targetColumns;
+        System.out.println("columnsVisitedForTable"+anyTableFilter.getTable()+"="+filteredColumns);
+        return filteredColumns;
     }
 
     private Expression appendOnCondition(Update updateCommand) {

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

@@ -123,7 +123,7 @@ public class TestMergeUsing extends TestBase {
                 GATHER_ORDERED_RESULTS_SQL,
                 "SELECT 1 AS ID, 'Marcy'||X||X AS NAME FROM SYSTEM_RANGE(1,1)",
                 3,
-                "Unique index or primary key violation: \"Merge using ON column expression, duplicate values found:keys[ID]:values:[1]:from:PUBLIC.SOURCE:alias:SOURCE:current row number:2:conflicting row number:1"
+                "Unique index or primary key violation: \"Merge using ON column expression, duplicate values found:key columns[ID]:values:[1]:from:PUBLIC.SOURCE:alias:SOURCE:current row number:2:conflicting row number:1"
                 );
         
         // Duplicate key updated 3 rows at once, only 1 expected
@@ -136,6 +136,26 @@ public class TestMergeUsing extends TestBase {
                 3,
                 "Duplicate key updated 3 rows at once, only 1 expected"
                 );        
+        // Missing target columns in ON expression
+        testMergeUsingException(
+                "CREATE TABLE PARENT AS (SELECT 1 AS ID, 'Marcy'||X AS NAME FROM SYSTEM_RANGE(1,3) );"+
+                        "CREATE TABLE SOURCE AS (SELECT X AS ID, 'Marcy'||X AS NAME FROM SYSTEM_RANGE(1,3)  );",
+                "MERGE INTO PARENT USING SOURCE ON (1 = SOURCE.ID) WHEN MATCHED THEN UPDATE SET PARENT.NAME = SOURCE.NAME||SOURCE.ID WHERE PARENT.ID = 2 DELETE WHERE PARENT.ID = 1 WHEN NOT MATCHED THEN INSERT (ID, NAME) VALUES (SOURCE.ID, SOURCE.NAME)",
+                GATHER_ORDERED_RESULTS_SQL,
+                "SELECT X AS ID, 'Marcy'||X||X AS NAME FROM SYSTEM_RANGE(2,2) UNION ALL SELECT X AS ID, 'Marcy'||X AS NAME FROM SYSTEM_RANGE(3,3)",
+                3,
+                "No references to target columns found in ON clause"
+                );        
+        // Missing source columns in ON expression
+        testMergeUsingException(
+                "CREATE TABLE PARENT AS (SELECT 1 AS ID, 'Marcy'||X AS NAME FROM SYSTEM_RANGE(1,3) );"+
+                        "CREATE TABLE SOURCE AS (SELECT X AS ID, 'Marcy'||X AS NAME FROM SYSTEM_RANGE(1,3)  );",
+                "MERGE INTO PARENT USING SOURCE ON (PARENT.ID = 1) WHEN MATCHED THEN UPDATE SET PARENT.NAME = SOURCE.NAME||SOURCE.ID WHERE PARENT.ID = 2 DELETE WHERE PARENT.ID = 1 WHEN NOT MATCHED THEN INSERT (ID, NAME) VALUES (SOURCE.ID, SOURCE.NAME)",
+                GATHER_ORDERED_RESULTS_SQL,
+                "SELECT X AS ID, 'Marcy'||X||X AS NAME FROM SYSTEM_RANGE(2,2) UNION ALL SELECT X AS ID, 'Marcy'||X AS NAME FROM SYSTEM_RANGE(3,3)",
+                3,
+                "No references to source columns found in ON clause"
+                );        
        }
 
     /**
@@ -192,6 +212,7 @@ public class TestMergeUsing extends TestBase {
      * @param gatherResultsSQL - a select which gathers the results of the merge from the target table
      * @param expectedResultsSQL - a select which returns the expected results in the target table
      * @param expectedRowUpdateCount - how many updates should be expected from the merge using
+     * @param exceptionMessage - the exception message expected
      * @throws Exception
      */
     private void testMergeUsingException(String setupSQL, String statementUnderTest, String gatherResultsSQL,
@@ -201,6 +222,9 @@ public class TestMergeUsing extends TestBase {
                      expectedResultsSQL,  expectedRowUpdateCount);
         }
         catch(RuntimeException|org.h2.jdbc.JdbcSQLException e){
+            if(!e.getMessage().contains(exceptionMessage)){
+                e.printStackTrace();
+            }
             assertContains(e.getMessage(),exceptionMessage);
             return;            
         }