Fix update count for ON DUPLICATE KEY UPDATE

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

@@ -181,11 +181,15 @@ public class Insert extends Prepared implements ResultTarget {
                     try {
                         table.addRow(session, newRow);
                     } catch (DbException de) {
-                        if (!handleOnDuplicate(de)) {
+                        if (handleOnDuplicate(de)) {
+                            // MySQL returns 2 for updated row
+                            // TODO: detect no-op change
+                            rowNumber++;
+                        } else {
                             // INSERT IGNORE case
                             rowNumber--;
-                            continue;
                         }
+                        continue;
                     }
                     generatedKeys.confirmRow(newRow);
                     session.log(table, UndoLogRecord.INSERT, newRow);
@@ -399,16 +403,17 @@ public class Insert extends Prepared implements ResultTarget {
         }
         buff.append(prepareUpdateCondition(foundIndex).getSQL());
         String sql = buff.toString();
-        Prepared command = session.prepare(sql);
+        Update command = (Update) session.prepare(sql);
+        command.setUpdateToCurrentValuesReturnsZero(true);
         for (Parameter param : command.getParameters()) {
             Parameter insertParam = parameters.get(param.getIndex());
             param.setValue(insertParam.getValue(session));
         }
-        command.update();
+        boolean result = command.update() > 0;
         for (String variableName : variableNames) {
             session.setVariable(variableName, ValueNull.INSTANCE);
         }
-        return true;
+        return result;
     }
 
     private Expression prepareUpdateCondition(Index foundIndex) {

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

@@ -49,6 +49,8 @@ public class Update extends Prepared {
     /** The limit expression as specified in the LIMIT clause. */
     private Expression limitExpr;
 
+    private boolean updateToCurrentValuesReturnsZero;
+
     private final ArrayList<Column> columns = New.arrayList();
     private final HashMap<Column, Expression> expressionMap  = new HashMap<>();
 
@@ -134,7 +136,7 @@ public class Update extends Prepared {
                         }
                         newRow.setValue(i, newValue);
                     }
-                    if (setOnUpdate) {
+                    if (setOnUpdate || updateToCurrentValuesReturnsZero) {
                         setOnUpdate = false;
                         for (int i = 0; i < columnCount; i++) {
                             // Use equals here to detect changes from numeric 0 to 0.0 and similar
@@ -152,6 +154,8 @@ public class Update extends Prepared {
                                     }
                                 }
                             }
+                        } else if (updateToCurrentValuesReturnsZero) {
+                            count--;
                         }
                     }
                     table.validateConvertUpdateSequence(session, newRow);
@@ -268,4 +272,14 @@ public class Update extends Prepared {
     public void setSourceTableFilter(TableFilter sourceTableFilter) {
         this.sourceTableFilter = sourceTableFilter;
     }
+
+    /**
+     * Sets expected update count for update to current values case.
+     *
+     * @param updateToCurrentValuesReturnsZero if zero should be returned as update
+     *        count if update set row to current values
+     */
+    public void setUpdateToCurrentValuesReturnsZero(boolean updateToCurrentValuesReturnsZero) {
+        this.updateToCurrentValuesReturnsZero = updateToCurrentValuesReturnsZero;
+    }
 }

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

@@ -63,8 +63,20 @@ public class TestCompatibility extends TestBase {
         stat.execute("create schema s2");
         stat.execute("create table s2.test(id int primary key, name varchar(255))");
         stat.execute("insert into s2.test(id, name) values(1, 'a')");
-        stat.execute("insert into s2.test(id, name) values(1, 'b') " +
-                "on duplicate key update name = values(name)");
+        assertEquals(2, stat.executeUpdate("insert into s2.test(id, name) values(1, 'b') " +
+                "on duplicate key update name = values(name)"));
+        assertEquals(0, stat.executeUpdate("insert into s2.test(id, name) values(1, 'b') " +
+                "on duplicate key update name = values(name)"));
+        assertEquals(1, stat.executeUpdate("insert into s2.test(id, name) values(2, 'c') " +
+                "on duplicate key update name = values(name)"));
+        ResultSet rs = stat.executeQuery("select id, name from s2.test order by id");
+        assertTrue(rs.next());
+        assertEquals(1, rs.getInt(1));
+        assertEquals("b", rs.getString(2));
+        assertTrue(rs.next());
+        assertEquals(2, rs.getInt(1));
+        assertEquals("c", rs.getString(2));
+        assertFalse(rs.next());
         stat.execute("drop schema s2 cascade");
         c.close();
     }