PDO Update

例子：

<?php
//构造PDO连接
$dbh = "mysql:host=localhost;dbname=test";
$db = new PDO($dbh, 'root', 'root123');
$db->query("set character set 'gbk'"); 

//更新数据
$sql = "UPDATE user SET email='xiaochen@163.com' WHERE username='小陈'";
$count = $db->exec($sql);
echo '更新 ',$count,' 条数据记录！';
$db = null;
?>