/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* JBoss, Home of Professional Open Source
* Copyright 2013 Red Hat Inc. and/or its affiliates and other contributors
* as indicated by the @authors tag. All rights reserved.
* See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU Lesser General Public License, v. 2.1.
* This program is distributed in the hope that it will be useful, but WITHOUT A
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
* PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
* You should have received a copy of the GNU Lesser General Public License,
* v.2.1 along with this distribution; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
package org.hibernate.hql.internal.ast.exec;
import java.util.ArrayList;
import java.util.List;
import org.hibernate.HibernateException;
import org.hibernate.dialect.Dialect;
import org.hibernate.engine.spi.QueryParameters;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.hql.internal.ast.HqlSqlWalker;
import org.hibernate.hql.internal.ast.SqlGenerator;
import org.hibernate.hql.internal.ast.tree.DeleteStatement;
import org.hibernate.internal.util.StringHelper;
import org.hibernate.param.ParameterSpecification;
import org.hibernate.persister.collection.AbstractCollectionPersister;
import org.hibernate.persister.entity.Queryable;
import org.hibernate.sql.Delete;
import org.hibernate.type.CollectionType;
import org.hibernate.type.Type;
import org.jboss.logging.Logger;
import antlr.RecognitionException;
import antlr.collections.AST;
/**
* Provides deletions in addition to the basic SQL delete statement being executed. Ex: cascading the delete into a
* many-to-many join table.
*
* @author Brett Meyer
*/
public class DeleteExecutor extends BasicExecutor {
private static final Logger LOG = Logger.getLogger( DeleteExecutor.class );
private final List<String> deletes = new ArrayList<String>();
private List<ParameterSpecification> parameterSpecifications;
public DeleteExecutor(HqlSqlWalker walker, Queryable persister) {
super( walker, persister );
final SessionFactoryImplementor factory = walker.getSessionFactoryHelper().getFactory();
final Dialect dialect = factory.getDialect();
try {
final DeleteStatement deleteStatement = (DeleteStatement) walker.getAST();
final String idSubselectWhere;
if ( deleteStatement.hasWhereClause() ) {
final AST whereClause = deleteStatement.getWhereClause();
final SqlGenerator gen = new SqlGenerator( factory );
gen.whereClause( whereClause );
parameterSpecifications = gen.getCollectedParameters();
idSubselectWhere = gen.getSQL().length() > 7 ? gen.getSQL() : "";
}
else {
parameterSpecifications = new ArrayList<ParameterSpecification>();
idSubselectWhere = "";
}
// If many-to-many, delete the FK row in the collection table.
for ( Type type : persister.getPropertyTypes() ) {
if ( type.isCollectionType() ) {
final CollectionType cType = (CollectionType) type;
final AbstractCollectionPersister cPersister = (AbstractCollectionPersister) factory
.getCollectionPersister( cType.getRole() );
if ( cPersister.isManyToMany() ) {
if ( persister.getIdentifierColumnNames().length > 1
&& !dialect.supportsTuplesInSubqueries() ) {
LOG.warn(
"This dialect is unable to cascade the delete into the many-to-many join table" +
" when the entity has multiple primary keys. Either properly setup cascading on" +
" the constraints or manually clear the associations prior to deleting the entities."
);
}
else {
final String idSubselect = "(select "
+ StringHelper.join( ", ", persister.getIdentifierColumnNames() ) + " from "
+ persister.getTableName() + idSubselectWhere + ")";
final String where = "(" + StringHelper.join( ", ", cPersister.getKeyColumnNames() )
+ ") in " + idSubselect;
final Delete delete = new Delete().setTableName( cPersister.getTableName() ).setWhere( where );
if ( factory.getSettings().isCommentsEnabled() ) {
delete.setComment( "delete FKs in join table" );
}
deletes.add( delete.toStatementString() );
}
}
}
}
}
catch (RecognitionException e) {
throw new HibernateException( "Unable to delete the FKs in the join table!", e );
}
}
@Override
public int execute(QueryParameters parameters, SessionImplementor session) throws HibernateException {
for (String delete : deletes) {
doExecute( parameters, session, delete, parameterSpecifications );
}
// finally, execute the original sql statement
return super.execute( parameters, session );
}
}