    public static function isHadSub($parent, $menuid =''){
        $sql = sprintf("SELECT * FROM `menus` WHERE `parent` = '%s' %s", $parent, $where);
    }
The software constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component.