Checking for valid email and if it exists

I have successfully been able to allow users to invite a friend by sending them an email with a unique invite code,

however I am trying to add to ability to check if it is a valid email address and if the email is already registered in another table 'users' (same database) as it would be a headache for someone who is already registered to receive invite emails.

I have tried to check for a valid email and if it exists by writing this script:

  function email_registered($email) {
  $email = sanitize($email);
  return (mysql_result(mysql_query("SELECT COUNT(`user_id`) FROM `users` WHERE `email` =   '$email'"), 0)  ==1) ? true : false;
}      


    if (filter_var($_POST['email'], FILTER_VALIDATE_EMAIL) === false) {
        $errors[] = 'A valid email address is required';
    }
    if (email_registered($_POST['email']) === true) {
        $errors[] = 'Sorry, the email '' . $_POST['email'] . '' is already in use';
    }  

This was successful for checking emails addresses when registering a user but registering a account was in the same table as already registered account. I am unsure how to use the same script in the invite code as I am trying to check an email in the registered separate table.

Currently it does not check if it is a valid email or if it exists.

The Full PHP:

include 'config.php';

function email_registered($email) {
$email = sanitize($email);
return (mysqli_result(mysqli_query("SELECT mysqli_num_rows()(`user_id`) FROM `users` WHERE `email` = '$email'"), 0)  ==1) ? true : false;
} 


if(!empty($_POST)){
if(!empty($_POST['email'])){

    $email = mysqli_real_escape_string($conn,$_POST['email']);         

    $length = 10;
    $inviteCode = "";
    $characters = "0123456789abcdefghijklmnopqrstuvwxyz";

    for ($p = 0; $p < $length; $p++) {
    $inviteCode .= $characters[mt_rand(10, strlen($characters))];
    }

function email_registered($email)
{
    if (!empty($email)) {
        $ret_val = false;

        $query = sprintf(
            "SELECT id FROM users WHERE email = '%s'",
            mysqli_real_escape_string($email)
        );

        $result = mysqli_query($query);
        $num_rows = mysqli_num_rows($result);
        if ($num_rows > 0) {
            //email exists
            ?> 
            <p>User Exists</p>
            <?php 

            $ret_val = true;
        } else {
            $query = sprintf(
                "SELECT id FROM invites WHERE email = '%s'",
                mysqli_real_escape_string($email)
            );

            $result = mysqli_query($query);
            $num_rows = mysqli_num_rows($result);
            if ($num_rows > 0) {
                //email exists
                ?>
                <p>User Exists</p>
                <?php

                $ret_val = true;
            }
        }
        return $ret_val;
    }
 }

else { 

     $query = mysqli_query($conn, "INSERT INTO `referrals` (`email`, `inviteCode`) VALUES   ('$email', '$inviteCode') "); }
     //you might want to consider checking more here such as $query == true as it can return other statuses that you may not want
     if($query){ 

  include 'userinvite.php';

     ?>
         <p> "Thank you for inviting your friends!"</p>
     <?php 

    }
    else{
    ?>
       <p>Sorry there must have been a problem</p>
    <?php
        die('Error querying database. ' . mysqli_error($conn));
    }
}
else {
?>
    <p>Please enter an email</p>
<?php
}
}
?>

I am just trying to check if the email is registered in the 'users' table and if the email entered is a valid email.

---

I think your main question is how to check if an email exists in another table. If that's wrong, let me know and I can update my answer :P Here's a rough draft of a function you should be able to use.

I'm assuming you have these two tables:

Table 1: users

||id||email||name||

Table 2: invites

||id||email||inviter_user_id||

You can use this function to check if the email exists in either table

<?php
    /**
     * Check if the given email already exists in the DB
     *
     * @param $email string the email to check
     */
    function email_exists($email)
    {
        if (!empty($email)) {
            $ret_val = false;

            $query = sprintf(
                "SELECT id FROM users WHERE email = '%s'",
                mysqli_real_escape_string($email)
            );

            $result = mysqli_query($query);
            $num_rows = mysqli_num_rows($result);
            if ($num_rows > 0) {
                //email exists
                $ret_val = true;
            } else {
                $query = sprintf(
                    "SELECT id FROM invites WHERE email = '%s'",
                    mysqli_real_escape_string($email)
                );

                $result = mysqli_query($query);
                $num_rows = mysqli_num_rows($result);
                if ($num_rows > 0) {
                    //email exists
                    $ret_val = true;
                }
            }
            return $ret_val;
        }
    }
?>

链接地址: http://www.djcxy.com/p/92814.html

上一篇: 全球邮件验证

下一篇: 检查有效的电子邮件，如果它存在