登录登记表问题 - Login Registration Form Issue

我正在为我的网站制作登录/注册表格。当我用一个新用户名注册为一个新用户时，即使数据库是空的，它读起来好像该用户名已经存在。我会试着引导你完成这方面的代码，但我不确定问题在哪里。

    if (isset($_POST['submit'])) {
    if(empty($_POST['username']) || empty($_POST['password']) || empty($_POST['email']) || empty($_POST['Fname'])){
        $errors[] = 'All fields are required.';
    }else{
        if ($users->user_exists($_POST['username']) === true) {
            $errors[] = 'That username already exists';
        }
        if(!ctype_alnum($_POST['username'])){
            $errors[] = 'Please enter a username with only alphabets and numbers';  
        }
        if (strlen($_POST['password']) <6){
            $errors[] = 'Your password must be atleast 6 characters';
        } else if (strlen($_POST['password']) >18){
            $errors[] = 'Your password cannot be more than 18 characters long';
        }
        if (filter_var($_POST['email'], FILTER_VALIDATE_EMAIL) === false) {
            $errors[] = 'Please enter a valid email address';
        }else if ($users->email_exists($_POST['email']) === true) {
            $errors[] = 'That email already exists.';
        }
    }
    if(empty($errors) === true){
        $username       = htmlentities($_POST['username']);
        $password       = $_POST['password'];
        $email          = htmlentities($_POST['email']);
        $firstName      = htmlentities($_POST['Fname']);
        $lastName       = htmlentities($_POST['Lname']);
        $accountType    = $_POST['account_type'];
        $users->register($username, $password, $email, $firstName, $lastName, $accountType);
        header('Location: register.php?success');
        exit();
    }
}

这是函数检查用户名和电子邮件是否已经存在

public function user_exists($username) {
        $query = $this->mysqli->prepare("SELECT COUNT(`id`) FROM `users` WHERE `username`= ?");
        $query->bind_param('s', $username);
        $query->execute();
        $rows = $query->fetch();
        if($rows == 1){
            return true;
        }else{
            return false;
        }
    }
public function email_exists($email) {
    $query = $this->mysqli->prepare("SELECT COUNT(`id`) FROM `users` WHERE `email`= ?");
    $query->bind_param('s', $email);
        $query->execute();
        $rows = $query->fetch();
        if($rows == 1){
            return true;
        }else{
            return false;
        }
}

和寄存器功能

public function register($username, $password, $email, $firstName, $lastName, $accountType){
    global $bcrypt; // making the $bcrypt variable global so we can use here
    $time       = time();
    $ip         = $_SERVER['REMOTE_ADDR']; // getting the users IP address
    $email_code = $email_code = uniqid('code_',true); // Creating a unique string.
    $password   = $bcrypt->genHash($password);
    $query  = $this->mysqli->prepare("INSERT INTO `users` (`username`, `password`, `email`, `ip`, `time`, `email_code`, `firstName`, `lastName`, `accountType`) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?) ");
    $query->bind_param('ssssissss',$username, $password,  $email, $ip, $time, $email_code, $firstName, $lastName, $accountType);

    $query->execute();
            }

我相信你的问题是public function user_exists($username)-中的这一行

$rows = $query->fetch();

$rows没有设置为查询中的值，只是在$query->fetch()成功时返回true。阅读mysqli_stmt::fetch-手册

在调用mysqli_stmt_fetch（）之前，应用程序必须绑定所有列。

尝试将其更改为-

public function user_exists($username) {
    $query = $this->mysqli->prepare("SELECT COUNT(`id`) FROM `users` WHERE `username`= ?");
    $query->bind_param('s', $username);
    $query->execute();
    // Bind the results       
    $query->bind_result($count);
    while($rows = $query->fetch()){
       if($count == 1){
          return true;
       }else{
          return false;
       }
    }
}

您还需要对public function email_exists($email) 执行此操作