Canit insert into my MYSQL table

Question

I am trying to make a registration form in which I have connected to the database and it can also check whether the username is unique or not but unfortunately, I can't insert the new data in my table. I would really appreciate if anyone could help me with this.

<?php
error_reporting(E_ALL ^ E_DEPRECATED);
include 'connect.inc.php'; 
if(isset($_POST['submit'])) {
    $username = mysql_real_escape_string($_POST['username']);
    $password = mysql_real_escape_string($_POST['password']); 
    $password2 = mysql_real_escape_string($_POST['password2']);       
    $firstname = mysql_real_escape_string($_POST['firstname']);
    $lastname = mysql_real_escape_string($_POST['lastname']);

    //md5 password
    $password_hash = md5($password);

    //check to see if the fields are empty
    if(empty($username) || empty($password)|| empty($firstname)|| empty($lastname)) {
        echo "Not all fields filled!<br /><br />";
        exit();
    }

    //check if password is equal

    if($password != $password2) {
        echo "Your Passwords Do Not Match.<br />";
        exit();
    } else { 
        $query = "SELECT `username` From `users` WHERE username='$username'"; 
        $result = mysql_query($query);

        if(mysql_num_rows($result) ==1) { 
            echo "Sorry, that user has already exists.";
            exit();
        } else {
            $query1= mysql_query("INSERT INTO `users` ('',username,password,firstname,lastname) VALUES ('','$username',     '$password_hash', '$firstname', '$lastname'");
            if($result1 = mysql_query($query1)) {
                echo "Registered Successfully";
            } else {
                echo "Sorry, You could not Register";           
            }
        }
    } 
} 

?>
<form action="" method="POST">
    Username:<br />
    <input type="text" name="username" /><br /><br />        

    Password:<br />
   <input type="password" name="password" /><br /><br />

    Confirm Password:<br />
    <input type="password" name="password2" /><br /><br />

    First Name:<br />
    <input type="text" name="firstname" /><br /><br />

    Last Name:<br />
    <input type="text" name="lastname" /><br /><br />

    <input type="submit" value="Register" name="submit" />
</form>

Answer 1

Your INSERT statement is missing a closing parenthesis.

$query1= mysql_query("INSERT INTO ... '$lastname'");

$query1= mysql_query("INSERT INTO ... '$lastname')");
                                                 ^

By the way, I find it easier when doing a single-row INSERT to use an alternative syntax, so the column names and the value are matched up:

$query1= mysql_query("INSERT INTO `users` SET
    username='$username',
    password='$password',
    firstname='$firstname',
    lastname='$lastname'");

That's easier to make sure you have the columns matched up to the right variables. Also there's no closing parenthesis to worry about.

See http://dev.mysql.com/doc/refman/5.7/en/insert.html for details on this syntax.

---

You should also abandon the deprecated mysql extension, and use PDO instead. Read this nice tutorial: https://phpdelusions.net/pdo

And Jay Blanchard is correct that your code is insecure. Security, like correctness, is not an add-on feature. You mention you are a beginner, but you should not start developing bad habits. Read https://blog.codinghorror.com/youre-probably-storing-passwords-incorrectly/

Answer 2

You want to probably insert the user id in the database.Define it as Autoincrement e remove the blank data from the query below:

Before:

$query1= mysql_query("INSERT INTO `users` ('',username,password,firstname,lastname) VALUES ('','$username',     '$password_hash', '$firstname', '$lastname'");

After:

$query1= mysql_query("INSERT INTO `users` (username,password,firstname,lastname) VALUES ('$username',     '$password_hash', '$firstname', '$lastname')") or die(mysql_error());

And you need also to replace the line with the code if($result1 = mysql_query($query1)) { by if($result1) {

Answer 3

Try using

$query1= mysql_query("INSERT INTO users (username,password,firstname,lastname) VALUES ('$username', '$password_hash', '$firstname', '$lastname'");

Answer 4

Replace your else block with

else {
    die('Error: ' . mysql_error());
    //echo "Sorry, You could not Register";
}

From your comment, your INSERT QUERY is wrong. To find out what is wrong with your SQL query, add var_export($query1, true) with die. i.e.

die('Error: ' . mysql_error().'<br>Info: '.var_export($query1, true));

My guess is that you are still using your old query which has '' as one of the column names.