/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
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
/** * Emulation of <tt>locate()</tt> on PostgreSQL * * @author Gavin King */
public class PositionSubstringFunction implements SQLFunction { @Override public boolean hasArguments() { return true; } @Override public boolean hasParenthesesIfNoArguments() { return true; } @Override public Type getReturnType(Type firstArgumentType, Mapping mapping) throws QueryException { return StandardBasicTypes.INTEGER; } @Override public String render(Type firstArgumentType, List args, SessionFactoryImplementor factory) throws QueryException { final boolean threeArgs = args.size() > 2; final Object pattern = args.get( 0 ); final Object string = args.get( 1 ); final Object start = threeArgs ? args.get( 2 ) : null; final 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(); } }