org.hibernate.sql.DerbyCaseFragment Maven / Gradle / Ivy
/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Middleware LLC.
*
* 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, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY 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
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*
*/
package org.hibernate.sql;
import java.util.Iterator;
import java.util.Map;
/**
* @author Simon Johnston
* @see org.hibernate.dialect.DerbyDialect
*/
public class DerbyCaseFragment extends CaseFragment {
/**
* From http://www.jroller.com/comments/kenlars99/Weblog/cloudscape_soon_to_be_derby
*
* The problem we had, was when Hibernate does a select with a case statement, for joined subclasses.
* This seems to be because there was no else at the end of the case statement (other dbs seem to not mind).
*/
public String toFragmentString() {
StringBuilder buf = new StringBuilder( cases.size() * 15 + 10 );
buf.append( "case" ); //$NON-NLS-1
Iterator iter = cases.entrySet().iterator();
while ( iter.hasNext() ) {
Map.Entry me = ( Map.Entry ) iter.next();
buf.append( " when " )//$NON-NLS-1
.append( me.getKey() )
.append( " is not null then " )//$NON-NLS-1
.append( me.getValue() );
}
// null is not considered the same type as Integer.
buf.append( " else -1" ); //$NON-NLS-1
buf.append( " end" ); //$NON-NLS-1
if ( returnColumnName != null ) {
buf.append( " as " )//$NON-NLS-1
.append( returnColumnName );
}
return buf.toString();
}
}