如何查看邮箱是否已被使用

Question

我使用 PHP 进行了表单验证。如果发生错误，错误消息将显示在每个输入列周围。我想检查一下这个邮箱是否被使用过。因此，我使用错误代码来定义是否使用输入电子邮件地址，然后显示“电子邮件已被使用”的错误消息。然而，结果变成了我输入的任何内容，它只显示“电子邮件已被使用”。有人可以帮我解决这个问题吗？谢谢！<?php  require_once('./conn.php');  $errorMsgs = array('nickname'=>'', 'email'=>'', 'password'=>'');    if(isset($_POST['submit'])) {    if(empty($_POST['nickname'])) {      $errorMsgs['nickname'] = "Please enter your nickname";    }    $email = $_POST['email'];    $password = $_POST['password'];        // checking the email is valid or empty    if(empty($_POST['email'])) {      $errorMsgs['email'] = "Please enter your email";    } else {      if(!filter_var($email, FILTER_VALIDATE_EMAIL)) {        $errorMsgs['email'] = "Please enter a valid email";      }    }    $errorCode = $conn->errno;    if($errorCode === 1062) {      $errorMsgs['email'] = "The email has been used";    }    // checking the password is valid or empty    if(empty($_POST['password'])) {      $errorMsgs['password'] = "Please enter your password";    } else {      if(!preg_match('/\w{8,}/', $password)) {        $errorMsgs['password'] = "Please enter at least 8 characters";      }    }        if(!array_filter($errorMsgs)) {    $sql = sprintf("INSERT INTO member (nickname, email, password) values ('%s', '%s', '%s')", $_POST['nickname'], $_POST['email'],$_POST['password']);    $result = $conn->query($sql);    if($result) {      header("Location: index.php");    }  }}?>

Answer 1

您必须检查该电子邮件是否存在于您的用户表中。像这样的东西。

<?php

  require_once('./conn.php');

  $errorMsgs = array('nickname'=>'', 'email'=>'', 'password'=>'');

  

  if(isset($_POST['submit'])) {

    if(empty($_POST['nickname'])) {

      $errorMsgs['nickname'] = "Please enter your nickname";

    }

    $email = $_POST['email'];

    $password = $_POST['password'];

    

    // checking the email is valid or empty

    if(empty($_POST['email'])) {

      $errorMsgs['email'] = "Please enter your email";

    } else {

      if(!filter_var($email, FILTER_VALIDATE_EMAIL)) {

        $errorMsgs['email'] = "Please enter a valid email";

      }

      else{

          //you should use sql parameter binding

     $email = $_POST['email'];

    $checkDuplicate= $conn->query("SELECT email FROM user_table where email = '$email'");

    if(!empty($checkDuplicate)) {

      $errorMsgs['email'] = "The email has been used";

    }

      }

    }

     

    // checking the password is valid or empty

    if(empty($_POST['password'])) {

      $errorMsgs['password'] = "Please enter your password";

    } else {

      if(!preg_match('/\w{8,}/', $password)) {

        $errorMsgs['password'] = "Please enter at least 8 characters";

      }

    }

    

    if(empty($errorMsgs)) { //you need to check if there's any error

    $sql = sprintf("INSERT INTO member (nickname, email, password) values ('%s', '%s', '%s')", $_POST['nickname'], $_POST['email'],$_POST['password']);

    $result = $conn->query($sql);

    if($result) {

      header("Location: index.php");

    }

  }

}

?>