PHP Sign up form error

Question

EDIT:

Hi I am trying to build a form and check if the email address is already taken during the sign up process. Currently I am trying this on my localhost. But whenever I sign up it says

Could not sign up.

Where am I mistaking? PHP code:

<?php
if (array_key_exists("submit", $_POST)) {

    $link = mysqli_connect("localhost", "root", "root", "form");
    if (mysqli_connect_error()) {

        die ("Database Connection Error");

    }
    else {
        $query = "SELECT id FROM 'users' WHERE email = '".mysqli_real_escape_string($link, $_POST['email'])."' LIMIT 1";
        $result = mysqli_query($link, $query);
        if (mysqli_num_rows($result) > 0) {
           echo  "That email address is taken.";
        }
        else {
            $query = "INSERT INTO 'users' ('name', 'email', 'password', 'number') VALUES ('".mysqli_real_escape_string($link, $_POST['name'])."', '".mysqli_real_escape_string($link, $_POST['email'])."', '".mysqli_real_escape_string($link, $_POST['password'])."', '".mysqli_real_escape_string($link, $_POST['number'])."')";
            if (!mysqli_query($link, $query)) {
                echo  "Could not sign up.";
            }
            else {
                echo "Sign up successful.";
            }
        }
    }
}
?>

Have you tried researching? There are existing questions like this https://stackoverflow.com/questions/2546314/php-mysql-mysqli-num-rows-expects-parameter-1-to-be-mysqli-result-boolean This could be considered a duplicate. — QHarr, Dec 19 '17 at 08:20
I already saw that. I could not understand the answer. Would you please elaborate? — Kumar Priyansh, Dec 19 '17 at 08:21
As in the link above mentions: The query either returned no rows or is erroneus, thus FALSE is returned. — QHarr, Dec 19 '17 at 08:23
https://apple.stackexchange.com/questions/69820/typing-a-backtick-on-mac-os-x-snow-leopard may help — Nigel Ren, Dec 19 '17 at 08:24
Also - unless your using a MySQL reserved word, you don't need to use any form of quotes, so try just removing the quotes and it should be OK. — Nigel Ren, Dec 19 '17 at 08:26
I did it. typed in backticks but still gives an error "could not sign up".. the warning is gone now — Kumar Priyansh, Dec 19 '17 at 08:26
Change `echo "Could not sign up.";` to `echo mysqli_error($link);` which should give you an error. — Nigel Ren, Dec 19 '17 at 08:32
Here's the error: `You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ''name', 'email', 'password', 'number') VALUES ('lucifer', 'lucifer@lucifer.com',' at line 1` — Kumar Priyansh, Dec 19 '17 at 08:35
So you didn't replace all of the quotes with back ticks then. — Nigel Ren, Dec 19 '17 at 08:44

score 0 · Accepted Answer · answered Dec 19 '17 at 08:38

You're using single quotes to delimit field and table names when you should be using back ticks. If you're unable to use back ticks, just omit them altogether - MySQL field and table names are case insensitive by default.

E.g.:

$query = "INSERT INTO users (name, email, password, number) VALUES ...

PHP Sign up form error

1 Answers1