mysql查询优化

    //获取列表
    public function getList($params, $pageSize, $p){
        $limit = ($p - 1) * $pageSize;
        $limit.=",{$pageSize}";
        $getWhere = $this -> getWhere($params);
        $sql = "SELECT SQL_CALC_FOUND_ROWS * from exp_catalog {$getWhere} order by `catid` desc LIMIT {$limit}";
        $sqlCount = "SELECT FOUND_ROWS() as count";
        $list = $this->db->find($sql);
        $count_data = $this->db->find($sqlCount);//返回数组
        $total = isset($count_data[0][‘count‘]) ? $count_data[0][‘count‘] : 0;
        return array(‘list‘ => $list, ‘total‘ => $total);
    }