php mysql PDO使用增删改查

<?php  
$dbh = new PDO('mysql:host=localhost;dbname=access_control', 'root', '');    
$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);    
$dbh->exec('set names utf8');   
/*添加*/  
//$sql = "INSERT INTO `user` SET `login`=:login AND `password`=:password";   
$sql = "INSERT INTO `user` (`login` ,`password`)VALUES (:login, :password)";  $stmt = $dbh->prepare($sql);  $stmt->execute(array(':login'=>'kevin2',':password'=>''));    
echo $dbh->lastinsertid();    
/*修改*/  
$sql = "UPDATE `user` SET `password`=:password WHERE `user_id`=:userId";    
$stmt = $dbh->prepare($sql);    
$stmt->execute(array(':userId'=>'7', ':password'=>'4607e782c4d86fd5364d7e4508bb10d9'));    
echo $stmt->rowCount();   
/*删除*/  
$sql = "DELETE FROM `user` WHERE `login` LIKE 'kevin_'"; //kevin%    
$stmt = $dbh->prepare($sql);    
$stmt->execute();    
echo $stmt->rowCount();    
/*查询*/  
$login = 'kevin%';    
$sql = "SELECT * FROM `user` WHERE `login` LIKE :login";    
$stmt = $dbh->prepare($sql);    
$stmt->execute(array(':login'=>$login));    
while($row = $stmt->fetch(PDO::FETCH_ASSOC)){       
 print_r($row);    
}    
print_r( $stmt->fetchAll(PDO::FETCH_ASSOC));   
?>