Db类下创建数据库连接方法和查询方法

Db类下创建数据库连接方法和查询方法

`<?php
class Db {
public $dsn;
public $user;
public $password;
public $pdo;

public function connect(){
    $this->pdo = new PDO($this->dsn,$this->user,$this->password);
}
public function __construct($dsn,$user,$password)
{
    $this->dsn = $dsn;
    $this->user = $user;
    $this->password = $password;
    $this->connect();
}
public function __destruct()
{
    $this->pdo = null;
}
public function select($sql){
    $stmt = $this->pdo->prepare($sql);
    $stmt->bindParam('uid',$uid,PDO::PARAM_INT);
    $stmt->execute();
    $user = $stmt->fetchAll(PDO::FETCH_ASSOC);
    foreach ($user as $v){
        echo '<pre>' . print_r($v, true);
    }
    return $stmt;
}

}

$db = new Db(‘mysql:host=localhost;dbname=apple;’,’root’,’root’);
if ($db->pdo){
echo ‘数据库连接成功！’;
}
echo ‘<hr>‘;

$sql = ‘SELECT * FROM user WHERE uid>=1’;
$user = $db->select($sql);
print_r($user);
`