Question

我使用MySQLi进行一些数据库处理，我不明白为什么我的代码无效。

// new connection
$mysqli = new mysqli(
 $config['database']['connect']['host'],
 $config['database']['connect']['username'],
 $config['database']['connect']['password'],
 $config['database']['connect']['name']
);

// verify connection
if (mysqli_connect_errno()) {
 printf("Connect failed: %s\n", mysqli_connect_error());
 exit();
}

// create prepared statement
if ($stmt = $mysqli->prepare('SELECT password FROM login_users WHERE user_name = ? LIMIT 1')) {
 $stmt->bind_param('s', $username);

 $username = 'gooduser';
 $password = md5('goodpass');

    $stmt->execute();
 $stmt->store_result();

 $_SESSION['messages'][] = 'Num rows: ' . $stmt->num_rows;

    $stmt->bind_result($pass);

 $_SESSION['messages'][] = 'Line 67';
 while ($stmt->fetch()) {
  $_SESSION['messages'][] = 'Line 69';
  if ($password == $pass) {
   $_SESSION['messages'][] = 'Success!';
  }
  else {
   $_SESSION['messages'][] = 'Bad pass';
  }
 }
 $_SESSION['messages'][] = 'Line 77';
 header('Location: ' . $_SESSION['redirect']);

    $stmt->close();
}
$mysqli->close();

使用“gooduser”和“goodpass”的用户名，这应该返回正确的行，它应该从那里开始工作。请注意$ _SESSION ['messages']是我的消息跟踪器。输出消息时，我得到了这个输出：

Num rows: 0
Line 67
Line 77

它正在跳过while循环，因为Num行为0。当通过查询更改片段以不使用绑定参数时，它可以工作：

// create prepared statement
if ($stmt = $mysqli->prepare('SELECT password FROM login_users WHERE user_name = "gooduser" LIMIT 1')) {
 //$stmt->bind_param('s', $username);

 //$username = 'gooduser';
 $password = md5('goodpass');

返回：

Num rows: 1
Line 67
Line 69
Success!
Line 77

有人在乎解释我在这里做错了什么吗？我正在尝试制作一个简单的登录脚本。

编辑：这是表结构：

-- Table structure for table `login_users`
--

CREATE TABLE `login_users` (
  `user_id` int(11) NOT NULL auto_increment,
  `user_name` varchar(30) NOT NULL default '',
  `password` varchar(70) NOT NULL default '',
  PRIMARY KEY  (`user_id`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=5 ;

更新：通过各种来源，尽管文档说明了v4.1，但看起来像v4.1.3中提供了MySQLi的完整功能集。某些功能有效，但其他功能（如bind_param）则不然。我已经和我的主人谈过了，我希望升级到最新版本。

Answer 1

在致电$username = 'gooduser';之前，您需要设置$stmt->bind_param('s', $username);，经过测试并且有效。

EDIT 对我来说，下面的工作，请复制粘贴到你的文件，看看你得到什么输出

    <?php
    ini_set('display_errors',1);
    error_reporting(E_ALL);
    // new connection
    $mysqli = new mysqli(
     $config['database']['connect']['host'],
     $config['database']['connect']['username'],
     $config['database']['connect']['password'],
     $config['database']['connect']['name']
    );


    // verify connection
    if (mysqli_connect_errno()) {
     printf("Connect failed: %s\n", mysqli_connect_error());
     exit();
    }

    // create prepared statement
    if ($stmt = $mysqli->prepare('SELECT password FROM login_users WHERE user_name = ? LIMIT 1')) {
        $username = 'gooduser';
 $password = md5('goodpass');
     $stmt->bind_param('s', $username);


        $stmt->execute();
     $stmt->store_result();

     $_SESSION['messages'][] = 'Num rows: ' . $stmt->num_rows;
    $stmt->bind_result($pass);


     $_SESSION['messages'][] = 'Line 67';
     while ($stmt->fetch()) {
      $_SESSION['messages'][] = 'Line 69';
      if ($password == $pass) {
       $_SESSION['messages'][] = 'Success!';
      }
      else {
       $_SESSION['messages'][] = 'Bad pass';
      }
     }
     $_SESSION['messages'][] = 'Line 77';
     //header('Location: ' . $_SESSION['redirect']);

        $stmt->close();
    }
    $mysqli->close();
    var_dump($_SESSION);

返回：

    array(1) {
      ["messages"]=>
      array(5) {
        [0]=>
        string(11) "Num rows: 1"
        [1]=>
        string(7) "Line 67"
        [2]=>
        string(7) "Line 69"
        [3]=>
        string(8) "Success!"
        [4]=>
        string(7) "Line 77"


 }
}

MySQLi SELECT绑定参数不返回一行

1 个答案: