* @return Result object
*/
Result executeMergeStatement(Session session) {
Type[] colTypes = baseTable.getColumnTypes();
Result resultOut = null;
RowSetNavigator generatedNavigator = null;
if (generatedIndexes != null) {
resultOut = Result.newUpdateCountResult(generatedResultMetaData,
0);
generatedNavigator = resultOut.getChainedResult().getNavigator();
}
int count = 0;
// data generated for non-matching rows
RowSetNavigatorClient newData = new RowSetNavigatorClient(8);
// rowset for update operation
RowSetNavigatorDataChange updateRowSet =
new RowSetNavigatorDataChange();
RangeVariable[] joinRangeIterators = targetRangeVariables;
// populate insert and update lists
RangeIterator[] rangeIterators =
new RangeIterator[joinRangeIterators.length];
for (int i = 0; i < joinRangeIterators.length; i++) {
rangeIterators[i] = joinRangeIterators[i].getIterator(session);
}
for (int currentIndex = 0; currentIndex >= 0; ) {
RangeIterator it = rangeIterators[currentIndex];
boolean beforeFirst = it.isBeforeFirst();
if (it.next()) {
if (currentIndex < joinRangeIterators.length - 1) {
currentIndex++;
continue;
}
} else {
if (currentIndex == 1 && beforeFirst
&& insertExpression != null) {
Object[] data =
getInsertData(session, colTypes,
insertExpression.nodes[0].nodes);
if (data != null) {
newData.add(data);
}
}
it.reset();
currentIndex--;
continue;
}
// row matches!
if (updateExpressions.length != 0) {
Row row = it.getCurrentRow(); // this is always the second iterator
Object[] data = getUpdatedData(session, targets, baseTable,
updateColumnMap,
updateExpressions, colTypes,
row.getData());
try {
updateRowSet.addRow(session, row, data, colTypes,
updateColumnMap);
} catch (HsqlException e) {
for (int i = 0; i < joinRangeIterators.length; i++) {
rangeIterators[i].reset();
}
throw Error.error(ErrorCode.X_21000);
}
}
}
for (int i = 0; i < joinRangeIterators.length; i++) {
rangeIterators[i].reset();
}
// run the transaction as a whole, updating and inserting where needed
// update any matched rows
if (updateExpressions.length != 0) {
count = update(session, baseTable, updateRowSet);
}
// insert any non-matched rows
if (newData.getSize() > 0) {
insertRowSet(session, generatedNavigator, newData);
count += newData.getSize();
}
if (insertExpression != null
&& baseTable.triggerLists[Trigger.INSERT_AFTER].length > 0) {
baseTable.fireTriggers(session, Trigger.INSERT_AFTER, newData);
}
if (resultOut == null) {
if (count == 1) {
return Result.updateOneResult;
}
return new Result(ResultConstants.UPDATECOUNT, count);
} else {
resultOut.setUpdateCount(count);
return resultOut;
}
}