@Override
public ResultInterface queryMeta() {
int columnCount = left.getColumnCount();
LocalResult result = new LocalResult(session, expressionArray, columnCount);
result.done();
return result;
}
/**
* Execute the query, writing the result to the target result.
*
* @param limit the maximum number of rows to return
* @param target the target result (null will return the result)
* @return the result set (if the target is not set).
*/
LocalResult query(int limit, ResultTarget target) {
fireBeforeSelectTriggers();
if (noCache || !session.getDatabase().getOptimizeReuseResults()) {
return queryWithoutCache(limit, target);
}
Value[] params = getParameterValues();
long now = session.getDatabase().getModificationDataId();
if (isEverything(ExpressionVisitor.DETERMINISTIC_VISITOR)) {
if (lastResult != null && !lastResult.isClosed() && limit == lastLimit) {
if (sameResultAsLast(session, params, lastParameters, lastEvaluated)) {
lastResult = lastResult.createShallowCopy(session);
if (lastResult != null) {
lastResult.reset();
return lastResult;
}
}
}
}
lastParameters = params;
closeLastResult();
LocalResult r = queryWithoutCache(limit, target);
lastResult = r;
this.lastEvaluated = now;
lastLimit = limit;
return r;
}
private void closeTemporaryResults() {
if (temporaryResults != null) {
for (LocalResult result : temporaryResults) {
result.close();
}
temporaryResults = null;
}
}
/**
* Remember the result set and close it as soon as the transaction is committed (if it needs to be
* closed). This is done to delete temporary files as soon as possible, and free object ids of
* temporary tables.
*
* @param result the temporary result set
*/
public void addTemporaryResult(LocalResult result) {
if (!result.needToClose()) {
return;
}
if (temporaryResults == null) {
temporaryResults = New.hashSet();
}
if (temporaryResults.size() < 100) {
// reference at most 100 result sets to avoid memory problems
temporaryResults.add(result);
}
}
private void closeLastResult() {
if (lastResult != null) {
lastResult.close();
}
}
protected LocalResult queryWithoutCache(int maxRows, ResultTarget target) {
int limitRows = maxRows == 0 ? -1 : maxRows;
if (limitExpr != null) {
Value v = limitExpr.getValue(session);
int l = v == ValueNull.INSTANCE ? -1 : v.getInt();
if (limitRows < 0) {
limitRows = l;
} else if (l >= 0) {
limitRows = Math.min(l, limitRows);
}
}
int columnCount = expressions.size();
LocalResult result = null;
if (target == null || !session.getDatabase().getSettings().optimizeInsertFromSelect) {
result = createLocalResult(result);
}
if (sort != null && (!sortUsingIndex || distinct)) {
result = createLocalResult(result);
result.setSortOrder(sort);
}
if (distinct && !isDistinctQuery) {
result = createLocalResult(result);
result.setDistinct();
}
if (randomAccessResult) {
result = createLocalResult(result);
result.setRandomAccess();
}
if (isGroupQuery && !isGroupSortedQuery) {
result = createLocalResult(result);
}
if (limitRows >= 0 || offsetExpr != null) {
result = createLocalResult(result);
}
topTableFilter.startQuery(session);
topTableFilter.reset();
boolean exclusive = isForUpdate && !isForUpdateMvcc;
if (isForUpdateMvcc) {
if (isGroupQuery) {
throw DbException.getUnsupportedException("FOR UPDATE && GROUP");
} else if (distinct) {
throw DbException.getUnsupportedException("FOR UPDATE && DISTINCT");
} else if (isQuickAggregateQuery) {
throw DbException.getUnsupportedException("FOR UPDATE && AGGREGATE");
} else if (topTableFilter.getJoin() != null) {
throw DbException.getUnsupportedException("FOR UPDATE && JOIN");
} else if (topTableFilter.getJoin() != null) {
throw DbException.getUnsupportedException("FOR UPDATE && JOIN");
}
}
topTableFilter.lock(session, exclusive, exclusive);
ResultTarget to = result != null ? result : target;
if (limitRows != 0) {
if (isQuickAggregateQuery) {
queryQuick(columnCount, to);
} else if (isGroupQuery) {
if (isGroupSortedQuery) {
queryGroupSorted(columnCount, to);
} else {
queryGroup(columnCount, result);
}
} else if (isDistinctQuery) {
queryDistinct(to, limitRows);
} else {
queryFlat(columnCount, to, limitRows);
}
}
if (offsetExpr != null) {
result.setOffset(offsetExpr.getValue(session).getInt());
}
if (limitRows >= 0) {
result.setLimit(limitRows);
}
if (result != null) {
result.done();
if (target != null) {
while (result.next()) {
target.addRow(result.currentRow());
}
result.close();
return null;
}
return result;
}
return null;
}
public ResultInterface queryMeta() {
LocalResult result = new LocalResult(session, expressionArray, visibleColumnCount);
result.done();
return result;
}
private void queryGroup(int columnCount, LocalResult result) {
ValueHashMap<HashMap<Expression, Object>> groups = ValueHashMap.newInstance();
int rowNumber = 0;
setCurrentRowNumber(0);
ValueArray defaultGroup = ValueArray.get(new Value[0]);
while (topTableFilter.next()) {
setCurrentRowNumber(rowNumber + 1);
if (condition == null || Boolean.TRUE.equals(condition.getBooleanValue(session))) {
Value key;
rowNumber++;
if (groupIndex == null) {
key = defaultGroup;
} else {
Value[] keyValues = new Value[groupIndex.length];
// update group
for (int i = 0; i < groupIndex.length; i++) {
int idx = groupIndex[i];
Expression expr = expressions.get(idx);
keyValues[i] = expr.getValue(session);
}
key = ValueArray.get(keyValues);
}
HashMap<Expression, Object> values = groups.get(key);
if (values == null) {
values = new HashMap<Expression, Object>();
groups.put(key, values);
}
currentGroup = values;
currentGroupRowId++;
int len = columnCount;
for (int i = 0; i < len; i++) {
if (groupByExpression == null || !groupByExpression[i]) {
Expression expr = expressions.get(i);
expr.updateAggregate(session);
}
}
if (sampleSize > 0 && rowNumber >= sampleSize) {
break;
}
}
}
if (groupIndex == null && groups.size() == 0) {
groups.put(defaultGroup, new HashMap<Expression, Object>());
}
ArrayList<Value> keys = groups.keys();
for (Value v : keys) {
ValueArray key = (ValueArray) v;
currentGroup = groups.get(key);
Value[] keyValues = key.getList();
Value[] row = new Value[columnCount];
for (int j = 0; groupIndex != null && j < groupIndex.length; j++) {
row[groupIndex[j]] = keyValues[j];
}
for (int j = 0; j < columnCount; j++) {
if (groupByExpression != null && groupByExpression[j]) {
continue;
}
Expression expr = expressions.get(j);
row[j] = expr.getValue(session);
}
if (isHavingNullOrFalse(row)) {
continue;
}
row = keepOnlyDistinct(row, columnCount);
result.addRow(row);
}
}
@Override
protected LocalResult queryWithoutCache(int maxRows, ResultTarget target) {
if (maxRows != 0) {
// maxRows is set (maxRows 0 means no limit)
int l;
if (limitExpr == null) {
l = -1;
} else {
Value v = limitExpr.getValue(session);
l = v == ValueNull.INSTANCE ? -1 : v.getInt();
}
if (l < 0) {
// for limitExpr, 0 means no rows, and -1 means no limit
l = maxRows;
} else {
l = Math.min(l, maxRows);
}
limitExpr = ValueExpression.get(ValueInt.get(l));
}
if (session.getDatabase().getSettings().optimizeInsertFromSelect) {
if (unionType == UNION_ALL && target != null) {
if (sort == null && !distinct && maxRows == 0 && offsetExpr == null && limitExpr == null) {
left.query(0, target);
right.query(0, target);
return null;
}
}
}
int columnCount = left.getColumnCount();
LocalResult result = new LocalResult(session, expressionArray, columnCount);
if (sort != null) {
result.setSortOrder(sort);
}
if (distinct) {
left.setDistinct(true);
right.setDistinct(true);
result.setDistinct();
}
if (randomAccessResult) {
result.setRandomAccess();
}
switch (unionType) {
case UNION:
case EXCEPT:
left.setDistinct(true);
right.setDistinct(true);
result.setDistinct();
break;
case UNION_ALL:
break;
case INTERSECT:
left.setDistinct(true);
right.setDistinct(true);
break;
default:
DbException.throwInternalError("type=" + unionType);
}
ResultInterface l = left.query(0);
ResultInterface r = right.query(0);
l.reset();
r.reset();
switch (unionType) {
case UNION_ALL:
case UNION:
{
while (l.next()) {
result.addRow(convert(l.currentRow(), columnCount));
}
while (r.next()) {
result.addRow(convert(r.currentRow(), columnCount));
}
break;
}
case EXCEPT:
{
while (l.next()) {
result.addRow(convert(l.currentRow(), columnCount));
}
while (r.next()) {
result.removeDistinct(convert(r.currentRow(), columnCount));
}
break;
}
case INTERSECT:
{
LocalResult temp = new LocalResult(session, expressionArray, columnCount);
temp.setDistinct();
temp.setRandomAccess();
while (l.next()) {
temp.addRow(convert(l.currentRow(), columnCount));
}
while (r.next()) {
Value[] values = convert(r.currentRow(), columnCount);
if (temp.containsDistinct(values)) {
result.addRow(values);
}
}
break;
}
default:
DbException.throwInternalError("type=" + unionType);
}
if (offsetExpr != null) {
result.setOffset(offsetExpr.getValue(session).getInt());
}
if (limitExpr != null) {
Value v = limitExpr.getValue(session);
if (v != ValueNull.INSTANCE) {
result.setLimit(v.getInt());
}
}
result.done();
if (target != null) {
while (result.next()) {
target.addRow(result.currentRow());
}
result.close();
return null;
}
return result;
}
public Cursor find(Session session, SearchRow first, SearchRow last) {
if (recursive) {
if (view.getRecursiveResult() != null) {
ResultInterface r = view.getRecursiveResult();
r.reset();
return new ViewCursor(table, r);
}
if (query == null) {
query = (Query) createSession.prepare(querySQL, true);
planSQL = query.getPlanSQL();
}
if (!(query instanceof SelectUnion)) {
throw DbException.get(ErrorCode.SYNTAX_ERROR_2, "recursive queries without UNION ALL");
}
SelectUnion union = (SelectUnion) query;
if (union.getUnionType() != SelectUnion.UNION_ALL) {
throw DbException.get(ErrorCode.SYNTAX_ERROR_2, "recursive queries without UNION ALL");
}
Query left = union.getLeft();
ResultInterface r = left.query(0);
LocalResult result = union.getEmptyResult();
while (r.next()) {
result.addRow(r.currentRow());
}
Query right = union.getRight();
r.reset();
view.setRecursiveResult(r);
while (true) {
r = right.query(0);
if (r.getRowCount() == 0) {
break;
}
while (r.next()) {
result.addRow(r.currentRow());
}
r.reset();
view.setRecursiveResult(r);
}
return new ViewCursor(table, result);
}
ArrayList<Parameter> paramList = query.getParameters();
for (int i = 0; originalParameters != null && i < originalParameters.size(); i++) {
Parameter orig = originalParameters.get(i);
int idx = orig.getIndex();
Value value = orig.getValue(session);
setParameter(paramList, idx, value);
}
int len;
if (first != null) {
len = first.getColumnCount();
} else if (last != null) {
len = last.getColumnCount();
} else {
len = 0;
}
int idx = originalParameters == null ? 0 : originalParameters.size();
idx += view.getParameterOffset();
for (int i = 0; i < len; i++) {
if (first != null) {
Value v = first.getValue(i);
if (v != null) {
int x = idx++;
setParameter(paramList, x, v);
}
}
// for equality, only one parameter is used (first == last)
if (last != null && indexMasks[i] != IndexCondition.EQUALITY) {
Value v = last.getValue(i);
if (v != null) {
int x = idx++;
setParameter(paramList, x, v);
}
}
}
ResultInterface result = query.query(0);
return new ViewCursor(table, result);
}