org.hibernate.dialect.function.PositionSubstringFunction Maven / Gradle / Ivy
/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2010, Red Hat Inc. 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 Inc.
*
* 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.dialect.function;
import java.util.List;
import org.hibernate.QueryException;
import org.hibernate.engine.spi.Mapping;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.type.StandardBasicTypes;
import org.hibernate.type.Type;
/**
* Emulation of locate() on PostgreSQL
* @author Gavin King
*/
public class PositionSubstringFunction implements SQLFunction {
public boolean hasArguments() {
return true;
}
public boolean hasParenthesesIfNoArguments() {
return true;
}
public Type getReturnType(Type firstArgumentType, Mapping mapping) throws QueryException {
return StandardBasicTypes.INTEGER;
}
public String render(Type firstArgumentType, List args, SessionFactoryImplementor factory) throws QueryException {
boolean threeArgs = args.size() > 2;
Object pattern = args.get(0);
Object string = args.get(1);
Object start = threeArgs ? args.get(2) : null;
StringBuilder buf = new StringBuilder();
if (threeArgs) buf.append('(');
buf.append("position(").append( pattern ).append(" in ");
if (threeArgs) buf.append( "substring(");
buf.append( string );
if (threeArgs) buf.append( ", " ).append( start ).append(')');
buf.append(')');
if (threeArgs) buf.append('+').append( start ).append("-1)");
return buf.toString();
}
}