Doctrine\DBAL\Platforms\PostgreSqlPlatform::getLocateExpression PHP Method

    public function getLocateExpression($str, $substr, $startPos = false)
    {
        if ($startPos !== false) {
            $str = $this->getSubstringExpression($str, $startPos);
            return 'CASE WHEN (POSITION(' . $substr . ' IN ' . $str . ') = 0) THEN 0 ELSE (POSITION(' . $substr . ' IN ' . $str . ') + ' . ($startPos - 1) . ') END';
        }
        return 'POSITION(' . $substr . ' IN ' . $str . ')';
    }