// $Id: MultiTableDeleteExecutor.java 11288 2007-03-15 11:38:45Z steve.ebersole@jboss.com $
package org.hibernate.hql.ast.exec;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.Iterator;
import org.hibernate.HibernateException;
import org.hibernate.engine.QueryParameters;
import org.hibernate.engine.SessionImplementor;
import org.hibernate.exception.JDBCExceptionHelper;
import org.hibernate.hql.ast.HqlSqlWalker;
import org.hibernate.hql.ast.tree.DeleteStatement;
import org.hibernate.hql.ast.tree.FromElement;
import org.hibernate.param.ParameterSpecification;
import org.hibernate.persister.entity.Queryable;
import org.hibernate.sql.Delete;
import org.hibernate.util.StringHelper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Implementation of MultiTableDeleteExecutor.
*
* @author Steve Ebersole
*/
public class MultiTableDeleteExecutor extends AbstractStatementExecutor {
private static final Logger log = LoggerFactory.getLogger( MultiTableDeleteExecutor.class );
private final Queryable persister;
private final String idInsertSelect;
private final String[] deletes;
public MultiTableDeleteExecutor(HqlSqlWalker walker) {
super( walker, log );
if ( !walker.getSessionFactoryHelper().getFactory().getDialect().supportsTemporaryTables() ) {
throw new HibernateException( "cannot perform multi-table deletes using dialect not supporting temp tables" );
}
DeleteStatement deleteStatement = ( DeleteStatement ) walker.getAST();
FromElement fromElement = deleteStatement.getFromClause().getFromElement();
String bulkTargetAlias = fromElement.getTableAlias();
this.persister = fromElement.getQueryable();
this.idInsertSelect = generateIdInsertSelect( persister, bulkTargetAlias, deleteStatement.getWhereClause() );
log.trace( "Generated ID-INSERT-SELECT SQL (multi-table delete) : " + idInsertSelect );
String[] tableNames = persister.getConstraintOrderedTableNameClosure();
String[][] columnNames = persister.getContraintOrderedTableKeyColumnClosure();
String idSubselect = generateIdSubselect( persister );
deletes = new String[tableNames.length];
for ( int i = tableNames.length - 1; i >= 0; i-- ) {
// TODO : an optimization here would be to consider cascade deletes and not gen those delete statements;
// the difficulty is the ordering of the tables here vs the cascade attributes on the persisters ->
// the table info gotten here should really be self-contained (i.e., a class representation
// defining all the needed attributes), then we could then get an array of those
final Delete delete = new Delete()
.setTableName( tableNames[i] )
.setWhere( "(" + StringHelper.join( ", ", columnNames[i] ) + ") IN (" + idSubselect + ")" );
if ( getFactory().getSettings().isCommentsEnabled() ) {
delete.setComment( "bulk delete" );
}
deletes[i] = delete.toStatementString();
}
}
public String[] getSqlStatements() {
return deletes;
}
public int execute(QueryParameters parameters, SessionImplementor session) throws HibernateException {
coordinateSharedCacheCleanup( session );
createTemporaryTableIfNecessary( persister, session );
try {
// First, save off the pertinent ids, saving the number of pertinent ids for return
PreparedStatement ps = null;
int resultCount = 0;
try {
try {
ps = session.getBatcher().prepareStatement( idInsertSelect );
Iterator paramSpecifications = getWalker().getParameters().iterator();
int pos = 1;
while ( paramSpecifications.hasNext() ) {
final ParameterSpecification paramSpec = ( ParameterSpecification ) paramSpecifications.next();
pos += paramSpec.bind( ps, parameters, session, pos );
}
resultCount = ps.executeUpdate();
}
finally {
if ( ps != null ) {
session.getBatcher().closeStatement( ps );
}
}
}
catch( SQLException e ) {
throw JDBCExceptionHelper.convert(
getFactory().getSQLExceptionConverter(),
e,
"could not insert/select ids for bulk delete",
idInsertSelect
);
}
// Start performing the deletes
for ( int i = 0; i < deletes.length; i++ ) {
try {
try {
ps = session.getBatcher().prepareStatement( deletes[i] );
ps.executeUpdate();
}
finally {
if ( ps != null ) {
session.getBatcher().closeStatement( ps );
}
}
}
catch( SQLException e ) {
throw JDBCExceptionHelper.convert(
getFactory().getSQLExceptionConverter(),
e,
"error performing bulk delete",
deletes[i]
);
}
}
return resultCount;
}
finally {
dropTemporaryTableIfNecessary( persister, session );
}
}
protected Queryable[] getAffectedQueryables() {
return new Queryable[] { persister };
}
}