//$Id: PositionSubstringFunction.java 6608 2005-04-29 15:32:30Z oneovthafew $
package org.hibernate.dialect.function;
import java.util.List;
import org.hibernate.Hibernate;
import org.hibernate.QueryException;
import org.hibernate.engine.Mapping;
import org.hibernate.engine.SessionFactoryImplementor;
import org.hibernate.type.Type;
/**
* Emulation of <tt>locate()</tt> on PostgreSQL
* @author Gavin King
*/
public class PositionSubstringFunction implements SQLFunction {
public Type getReturnType(Type columnType, Mapping mapping) throws QueryException {
return Hibernate.INTEGER;
}
public boolean hasArguments() {
return true;
}
public boolean hasParenthesesIfNoArguments() {
return true;
}
public String render(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;
StringBuffer buf = new StringBuffer();
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();
}
}
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