db_mysql::count PHP Method

    public function count($table, $cond = array())
    {
        $cond = cond_to_sqladd($cond);
        $sql = "SELECT COUNT(*) AS num FROM `{$table}` {$cond}";
        $arr = $this->find_one($sql);
        return !empty($arr) ? intval($arr['num']) : $arr;
    }