PHP中PDO的用法

//PDO：数据访问抽象层
//dsn：数据源：
//带有事务功能：
$dsn = "mysql:host=localhost;dbname=mydb";
//造pdo对象
$pdo = new PDO($dsn,"root","123");
//设置为异常模式
$pdo->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION );

try
{
 //写SQL语句
 $sql = "insert into Nation values('n009','藏族')";
 $sql1 = "insert into Nation values('n001','藏族')";
 //$sql2 = "insert into Nation values('n012','藏族')";
 
 //启动事务
 $pdo->beginTransaction();
 
 //执行SQL语句
 $pdo->exec($sql);
 $pdo->exec($sql1);
 //$pdo->exec($sql2);
 
 $pdo->commit();
}
catch(PDOException $e)
{
 //echo $e->getMessage();
 //回滚事务
 $pdo->rollBack();
}

/*foreach($a as $v)
{
 var_dump($v);
}*/

第二特点：可以防止SQL注入攻击

<?php

//2.可以防止SQL注入攻击
$dsn="mysql:host=localhost;dbname=mydb";
$pdo = new PDO($dsn,"root","123");

$sql = "insert into Nation values(?,?)";

//将一条SQL语句放到服务器等待执行
$stm = $pdo->prepare($sql);

/*//绑定参数
$stm->bindParam(1,$code);
$stm->bindParam(2,$name);

//给变量赋值
$code = "n030";
$name = "哈空间";*/

$attr = array("n031","客户");
//执行预处理语句,执行成功返回true，执行失败返回false
if($stm->execute($attr))
{
    //var_dump($stm->fetch());
    //var_dump($stm->fetchAll(PDO::FETCH_ASSOC));
}




?>