PHP MYSQLI 调用成员函数 bind_param(） - PHP MYSQLI Call to a member function bind_param()

PHP MYSQLI Call to a member function bind_param()

我的代码是

$query1 = "SELECT `user_id` FROM `it_user` WHERE (user_email_address = ? AND user_mobile_number_verified = NULL)";
          $stmt1 = $mysqli->prepare($query1);
          $stmt1->bind_param("s",$email);
          $stmt1->execute();
          if ($stmt1->affected_rows == 1) {
            //set registration flag to 1 stating that the users mobile number is already verified
            echo '<meta http-equiv="refresh" content="0; URL=''../signin/''"/>';
          }
          else
          {
            $registration_flag = 2;  
            //redirect user to error page
            //echo '<meta http-equiv="refresh" content="0; URL=''../error/''"/>'; 
          }

我收到此错误：：

在第 62 行的 ***** 中的非对象上调用成员函数 bind_param（）

由于我的电子邮件变量正在工作，查询也是如此。

使用 NULL 安全运算符并编写如下代码：-

  $mobile = NULL; // NOTE: no quotes - using php NULL
  $query1 = "SELECT `user_id` FROM `it_user` WHERE user_email_address = ? AND user_mobile_number_verified <=> ?";
  $stmt1 = $mysqli->prepare($query1);
  $stmt1->bind_param("s",$email);
  $stmt1->bind_param($mobile);
  $stmt1->execute();

希望对您有所帮助：-）