pdo连接数据

<?php

//1.操作其它数据库
//2.事务功能
//3.防止SQL注入攻击

//造PDO对象
//$dsn = "mysql:dbname=mydb;host=localhost"; //数据源
//$pdo = new PDO($dsn,"root","123");

//写SQL语句
//$sql = "select * from nation";
//$sql = "insert into nation values('n077','数据')";

//执行,返回的是PDOStatement对象
//$a = $pdo->query($sql); //执行查询
//$a = $pdo->exec($sql); //执行其他语句

//var_dump($a);

//$arr = $attr->fetchAll(PDO::FETCH_BOTH);
//var_dump($arr);

//事务功能
//事务：能够控制语句同时成功同时失败，失败时可以回滚

$dsn = "mysql:dbname=mydb;host=localhost";
$pdo = new PDO($dsn,"root","123");

//设置异常模式
$pdo->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION);

try
{
//开启事务
$pdo ->beginTransaction();

$sql1 = "insert into nation values('n080','是删')";
$sql2 = "insert into nation values('n070','好几款')";
$sql3 = "insert into nation values('n075','好几款')";

$pdo->exec($sql1);
$pdo->exec($sql2);
$pdo->exec($sql3);

//提交
$pdo->commit();
}
catch(Exception $e)
{
//抓住try里面出现的错误，并且处理
//echo $e->getMessage(); //获取异常信息

//回滚
$pdo->rollBack();
}
//final()
//{
//最终执行，无论以上try代码有没有出错，都会执行
//}

?>