/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.openjpa.jdbc.kernel.exps;
import java.sql.SQLException;
import org.apache.openjpa.jdbc.conf.JDBCConfiguration;
import org.apache.openjpa.jdbc.kernel.JDBCFetchConfiguration;
import org.apache.openjpa.jdbc.kernel.JDBCStoreQuery;
import org.apache.openjpa.jdbc.meta.ClassMapping;
import org.apache.openjpa.jdbc.meta.JavaSQLTypes;
import org.apache.openjpa.jdbc.sql.Result;
import org.apache.openjpa.jdbc.sql.SQLBuffer;
import org.apache.openjpa.jdbc.sql.Select;
import org.apache.openjpa.kernel.Filters;
import org.apache.openjpa.kernel.exps.ExpressionVisitor;
import org.apache.openjpa.kernel.exps.QueryExpressions;
import org.apache.openjpa.kernel.exps.Subquery;
import org.apache.openjpa.kernel.exps.Value;
import org.apache.openjpa.meta.ClassMetaData;
/**
* A subquery.
*
* @author Abe White
*/
public class SubQ
extends AbstractVal
implements Subquery {
private final ClassMapping _candidate;
private final boolean _subs;
private String _subqAlias;
private final SelectConstructor _cons = new SelectConstructor();
private Class _type = null;
private ClassMetaData _meta = null;
private QueryExpressions _exps = null;
private Select _select = null;
/**
* Constructor. Supply candidate, whether subclasses are included in
* the query, and the query alias.
*/
public SubQ(ClassMapping candidate, boolean subs, String alias) {
_candidate = candidate;
_subs = subs;
_subqAlias = alias;
_select = (((JDBCConfiguration) candidate.getMappingRepository().
getConfiguration()).getSQLFactoryInstance().newSelect());
_cons.setSubselect(_select);
}
public Object getSelect() {
return _select;
}
/**
* Return the subquery candidate type.
*/
public ClassMapping getCandidate() {
return _candidate;
}
public boolean getSubs() {
return _subs;
}
public void setSubqAlias(String subqAlias) {
_subqAlias = subqAlias;
}
public String getSubqAlias() {
return _subqAlias;
}
public Class getType() {
if (_exps != null && _type == null) {
if (_exps.projections.length == 0)
return _candidate.getDescribedType();
if (_exps.projections.length == 1)
return _exps.projections[0].getType();
}
return _type;
}
public void setImplicitType(Class type) {
if (_exps != null && _exps.projections.length == 1)
_exps.projections[0].setImplicitType(type);
_type = type;
}
public ClassMetaData getMetaData() {
return _meta;
}
public void setMetaData(ClassMetaData meta) {
_meta = meta;
}
public String getCandidateAlias() {
return _subqAlias;
}
public void setQueryExpressions(QueryExpressions query) {
_exps = query;
_select.setContext(query.ctx());
}
public ExpState initialize(Select sel, ExpContext ctx, int flags) {
Select select = JDBCStoreQuery.getThreadLocalSelect(_select);
select.setParent(sel, null);
if (_exps.projections.length == 1) {
return ((Val) _exps.projections[0]).initialize(select, ctx, flags);
}
return ExpState.NULL;
}
public Object toDataStoreValue(Select sel, ExpContext ctx, ExpState state,
Object val) {
if (_exps.projections.length == 0)
return _candidate.toDataStoreValue(val,
_candidate.getPrimaryKeyColumns(), ctx.store);
if (_exps.projections.length == 1)
return ((Val) _exps.projections[0]).toDataStoreValue(sel, ctx,
state, val);
return val;
}
public void select(Select sel, ExpContext ctx, ExpState state,
boolean pks) {
selectColumns(sel, ctx, state, pks);
}
public void selectColumns(Select sel, ExpContext ctx, ExpState state,
boolean pks) {
sel.select(newSQLBuffer(sel, ctx, state), this);
}
public void groupBy(Select sel, ExpContext ctx, ExpState state) {
sel.groupBy(newSQLBuffer(sel, ctx, state));
}
public void orderBy(Select sel, ExpContext ctx, ExpState state,
boolean asc) {
sel.orderBy(newSQLBuffer(sel, ctx, state), asc, false, getSelectAs());
}
private SQLBuffer newSQLBuffer(Select sel, ExpContext ctx, ExpState state) {
SQLBuffer buf = new SQLBuffer(ctx.store.getDBDictionary());
appendTo(sel, ctx, state, buf, 0);
return buf;
}
public Object load(ExpContext ctx, ExpState state, Result res)
throws SQLException {
return Filters.convert(res.getObject(this,
JavaSQLTypes.JDBC_DEFAULT, null), getType());
}
public void calculateValue(Select sel, ExpContext ctx, ExpState state,
Val other, ExpState otherState) {
Value[] projs = _exps.projections;
for (int i = 0; i < projs.length; i++) {
if (projs[i] instanceof GeneralCaseExpression) {
((GeneralCaseExpression)projs[i]).setOtherPath(other);
((GeneralCaseExpression)projs[i]).setOtherState(otherState);
} else if (projs[i] instanceof SimpleCaseExpression) {
((SimpleCaseExpression)projs[i]).setOtherPath(other);
((SimpleCaseExpression)projs[i]).setOtherState(otherState);
} else if (projs[i] instanceof NullIfExpression) {
((NullIfExpression)projs[i]).setOtherPath(other);
((NullIfExpression)projs[i]).setOtherState(otherState);
} else if (projs[i] instanceof CoalesceExpression) {
((CoalesceExpression)projs[i]).setOtherPath(other);
((CoalesceExpression)projs[i]).setOtherState(otherState);
}
}
}
public int length(Select sel, ExpContext ctx, ExpState state) {
return 1;
}
public void appendTo(Select sel, ExpContext ctx, ExpState state,
SQLBuffer sql, int index) {
appendTo(sel, ctx, state, sql, index, false);
}
private void appendTo(Select sel, ExpContext ctx, ExpState state,
SQLBuffer sql, int index, boolean size) {
QueryExpressionsState substate = new QueryExpressionsState();
Select sub = _cons.evaluate(ctx, sel, _subqAlias, _exps, substate);
_cons.select(sub, ctx, _candidate, _subs, _exps, substate,
JDBCFetchConfiguration.EAGER_NONE);
if (size)
sql.appendCount(sub, ctx.fetch);
else
sql.append(sub, ctx.fetch);
}
public void appendIsEmpty(Select sel, ExpContext ctx, ExpState state,
SQLBuffer sql) {
sql.append("NOT EXISTS ");
appendTo(sel, ctx, state, sql, 0);
}
public void appendIsNotEmpty(Select sel, ExpContext ctx, ExpState state,
SQLBuffer sql) {
sql.append("EXISTS ");
appendTo(sel, ctx, state, sql, 0);
}
public void appendSize(Select sel, ExpContext ctx, ExpState state,
SQLBuffer sql) {
appendTo(sel, ctx, state, sql, 0, true);
}
public void acceptVisit(ExpressionVisitor visitor) {
visitor.enter(this);
for (int i = 0; i < _exps.projections.length; i++)
_exps.projections[i].acceptVisit(visitor);
if (_exps.filter != null)
_exps.filter.acceptVisit(visitor);
for (int i = 0; i < _exps.grouping.length; i++)
_exps.grouping[i].acceptVisit(visitor);
if (_exps.having != null)
_exps.having.acceptVisit(visitor);
for (int i = 0; i < _exps.ordering.length; i++)
_exps.ordering[i].acceptVisit(visitor);
visitor.exit(this);
}
}