注册表格PHP

Question

I am a beginner in PHP & MySQL, I am trying to create this register form for a project I am working on currently, here is the PHP script, btw.. If there is a lot of mistakes, it is because I have just started!

The problem I am having is that it does not check the database if the email or username match, because if it did, it should reject.

PHP code:

    <?php

//register php

error_reporting(0);

$regUsername = $_POST['reg-username'];
$regEmail = $_POST['reg-email'];
$regPassword = $_POST['reg-password'];

if(isset($regUsername) && isset($regEmail) && isset($regPassword)){
        $connect = mysql_connect('localhost', 'root', '');
        $selectDB = mysql_select_db('supermazad');
        $query = mysql_query("INSERT INTO users (username, email, password) VALUES ('$regUsername', '$regEmail', '$regPassword')");
        $checkIfSame = mysql_query("SELECT * FROM users WHERE username AND email LIKE '$query' ");
        echo '<h1 class="successMessage">You have successfully registered!</h1>';
}
            if($regUsername || $regEmail == $checkIfSame){
            echo '<h1 class="errorMessage">The username or e-mail already exists.</h1>';
        }

?>

Answer 1

You are trying to check if the username and email already exist in the database after inserting the username and email into the database. You should check beforehand either via a select with the username and email provided in the registraton, or by placing a unique key constraint on username and email fields.

Answer 2

1. Please use mysqli instead of mysql because it's safer
2. remove error_reporting(0)
3. don't use "like" because it might have many result
4. syntax error on the mysql query

try this one just debug if there are error but I think this works

    $regUsername    = $_POST['reg-username'];
$regEmail       = $_POST['reg-email'];
$regPassword    = $_POST['reg-password'];

if(isset($regUsername) && isset($regEmail) && isset($regPassword)){
        $mysqli         = mysqli_connect("localhost","root","","supermazad") or die("Error " . mysqli_error($mysqli)); 
        $queryInsert    = "INSERT INTO users (username, email, password) 
                            VALUES 
                          ('$regUsername', '$regEmail', '$regPassword')"; 
        mysqli_query($mysqli, $queryInsert); //this will insert the data from db

        $queryUser  = "SELECT username,email FROM users WHERE username = '$regUsername' AND email = '$regEmail'"; // this will authenticate and uses an exact match
        $result     = $mysqli->query($queryUser);
        $row        = mysqli_fetch_array($result);

        echo '<h1 class="successMessage">You have successfully registered!</h1>';
}
            if($regUsername == $row['username'] && $regEmail == $row['email']){ //this check if email and username are match with database $row['username'] store username from mysql field and $row['email'] do the same
            echo '<h1 class="errorMessage">The username or e-mail already exists.</h1>';
        }

by the way this is normal for a beginner but please improve your coding in the near future, make it cleaner and organize

Answer 3

I think you should do it like this after $selectDB = mysql_select_db('supermazad'); :

$checkIfSame = mysql_query("SELECT * FROM users WHERE username LIKE '".$regUsername."' OR email LIKE '".$regEmail."' ");
if (mysql_num_rows($checkIfSame ) > 0) {
    echo '<h1 class="errorMessage">The username or e-mail already exists.</h1>';
} else {
    //insert new user here
    $query = mysql_query("INSERT INTO users (username, email, password) VALUES ('$regUsername', '$regEmail', '$regPassword')");
}

Also, you have this in your post :

if the email or username match

so you should be using OR , not AND

Answer 4

Try this:

$checkIfSame = mysql_query("SELECT * FROM users WHERE username LIKE '".$regUsername."' OR email LIKE '".$regEmail."' ");
if (mysql_num_rows($checkIfSame ) > 0) {
    echo '<h1 class="errorMessage">The username or e-mail already exists.</h1>';
} else {
    //insert new user here
    $query = mysql_query("INSERT INTO users (username, email, password) VALUES ('$regUsername', '$regEmail', '$regPassword')");
}