$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) );