致命错误：调用未定义的方法 mysqli::bind_param()

我在这里挑不出毛病，你帮忙吗？这是我的错误

致命错误：调用未定义的方法 mysqli::bind_param()

我不知道出了什么问题

        <?php
      if($_SERVER['REQUEST_METHOD'] == 'POST' && isset($_POST)) 
       {

          $login    = $_POST['login'];
          $password = $_POST['password'];
          $email    = $_POST['email'];

        if(empty($login) || empty($password) || empty($email))
        {
          die('Comeplete all text.');
        }
        elseif(!filter_var($email, FILTER_VALIDATE_EMAIL)) 
        {
         die('Nie poprawny adres E-mail.');
        }
        else
        {   
         include_once('config.php');

         $mysqli = new mysqli('****', '******', '*****') or die ('Fatal Error: '.mysql_error());

         if($mysqli -> connect_error) 
          die('Error Connection:'.$mysqli -> connect_error.'['.$mysqli -> connect_errno.']');


         $login     = trim(htmlspecialchars($mysqli -> real_escape_string($login)));
         $password  = hash('sha256', trim(htmlspecialchars($mysqli -> real_escape_string($password))));
         $email     = trim(htmlspecialchars($mysqli -> real_escape_string($email)));
         $ip        = $_SERVER['REMOTE_ADDR'];


         $stmt = $mysqli -> prepare("INSERT INTO `user`(`id_user`, `login`,`password`,`email`,`added`,`ip`) VALUES('', ? , ? , ? , now(), ?)");
         $stmt = $mysqli -> bind_param("ssss", $login, $password, $email, $ip);
         if ($stmt) {
            $stmt->execute();

          echo 'Success';
         }
        }
      }


    ?>
 </section> 
</body>
</html>

问题是，你正在使用bind_paramMySQL 上的函数而不是$stmt多变的。

问题出在这一行：

 $stmt = $mysqli -> prepare("INSERT INTO `user`(`id_user`, `login`,`password`,`email`,`added`,`ip`) VALUES('', ? , ? , ? , now(), ?)");
 $stmt = $mysqli -> bind_param("ssss", $login, $password, $email, $ip);

而不是输入：

$stmt = $mysqli->bind_param("ssss", $login, $password, $email, $ip);

您应该输入：

$stmt = $stmt->bind_param("ssss", $login, $password, $email, $ip);

自从bind_param方法仅适用于mysqli_stmt班级。而不是mysqli.

查看文档here.