1)总的比较
PDO
MySQLi
数据库支持
12种不同的数据库支持
支持MySQL
API
OOP
OOP + 过程
Connection
Easy
Easy
命名参数
支持
不支持
对象映射支持
支持
支持
预处理语句
(客户端)
支持
不支持
性能
快
快
支持存储过程
支持
支持
2 连接方式
先来看下两者连接数据库的方式:
//PDO
$pdo = new PDO("mysql:host=localhost;dbname=database", 'username', 'password');//mysqli, 面向过程方式
$mysqli = mysqli_connect('localhost','username','password','database');//mysqli, 面向对象
$mysqli = new mysqli('localhost','username','password','database');
3 数据库支持
PDO支持多种数据库,但MYSQLI只支持MYSQL
4 命名参数name parameter
PDO的方式:
$params = array(':username' => 'test', ':email' => $mail, ':last_login' => time() - 3600);$pdo->prepare('SELECT * FROM users
WHERE username = :username
AND email = :email
AND last_login > :last_login');
而MYSQLI则麻烦点,不支持这样,只能:
$query = $mysqli->prepare('SELECT * FROM users
WHERE username = ?
AND email = ?
AND last_login > ?');$query->bind_param('sss', 'test', $mail, time() - 3600);$query->execute();
这样的话,一个个对问号的顺序,也比较麻烦,不大方便。
5 ORM映射的支持
比如有个类user,如下:
classUser
{public $id;public $first_name;public $last_name;public functioninfo()
{return '#' . $this->id . ': ' . $this->first_name . ' ' . $this->last_name;
}
}$query = "SELECT id, first_name, last_name FROM users";//PDO
$result = $pdo->query($query);$result->setFetchMode(PDO::FETCH_CLASS, 'User');while ($user = $result->fetch())
{echo $user->info() . "\n";
}
MYSQLI用面向过程的方式:
if ($result = mysqli_query($mysqli, $query)) {while ($user = mysqli_fetch_object($result, 'User')) {echo $user->info()."\n";
}
}
MYSQLI采用面向过程的方式:
//MySQLi, object oriented way
if ($result = $mysqli->query($query)) {while ($user = $result->fetch_object('User')) {echo $user->info()."\n";
}
}
6 防止SQL注入方面:
PDO 手工设置
$username = PDO::quote($_GET['username']);$pdo->query("SELECT * FROM users WHERE username = $username");
使用mysqli
$username = mysqli_real_escape_string($_GET['username']);$mysqli->query("SELECT * FROM users WHERE username = '$username'");
7 preparestament
PDO方式:
$pdo->prepare('SELECT * FROM users WHERE username = :username');$pdo->execute(array(':username' => $_GET['username']));
MYSQLI:
$query = $mysqli->prepare('SELECT * FROM users WHERE username = ?');$query->bind_param('s', $_GET['username']);$query->execute();