下面我們要建立一個模型類用來連線資料庫

我們在lib目錄下建一個model.php

<?php
namespace core\lib;
class Model extends \PDO
{
public function __construct()
    {
$dsn = 'mysql:host=localhost;dbname=test';
$username = 'root';
$passwd = 'root';
try {//如果連線資料庫異常，就顯示錯誤資訊
parent::__construct($dsn,$username,$passwd);
        } catch 
 
(\PDOException $e) {
            p($e->getMessage());
        }
    }
}

<?php
namespace app\controllers;
use core\lib\Model;
class IndexController
{
public function index()
    {
$model = new Model();
$sql = 'select * from up';
$res = $model->query($sql);
        p(
 
$res->fetchAll());
    }
}