Oracle 11g Extractvalue DQL function for Doctrine

ExtractvalueFunction.php

/**
 * This is the custom extractvalue function for doctrine. 
 * 
 * www.eftakhairul.com
 */


use Doctrine\ORM\Query\Lexer;
use Doctrine\ORM\Query\AST\Functions\FunctionNode;

/**
 * ExtractvalueFunction ::= "EXTRACTVALUE" "(" StateFieldPathExpression, InParameter")"
 * ExtractvalueFunction ::= "EXTRACTVALUE" "(" columnName, searchPattern ")"
 *
 * 
 * @author Eftakhairul Islam <eftakhairul.islam@codemate.com>
 */
class ExtractvalueFunction extends FunctionNode
{
    public $columnName;
    public $searchPattern;

    public function getSql(\Doctrine\ORM\Query\SqlWalker $sqlWalker)
    {
        return 'EXTRACTVALUE(' .
            $this->columnName->dispatch($sqlWalker) . ',' .
            $this->searchPattern->dispatch($sqlWalker) .
        ')';
    }    

    public function parse(\Doctrine\ORM\Query\Parser $parser)
    {
        $parser->match(Lexer::T_IDENTIFIER);
        $parser->match(Lexer::T_OPEN_PARENTHESIS);
        $this->columnName = $parser->StateFieldPathExpression();
        $parser->match(Lexer::T_COMMA);
        $this->searchPattern = $parser->InParameter();
        $parser->match(Lexer::T_CLOSE_PARENTHESIS);
    }
}