How to limit user registration

Question

How do i limit the user registration in the registration page? i want to limit the user that can register to only 2 users. and if another user want to register, they will have a notice "Registration is Full".

Help me, i dont know what to do now, im looking for the answer for the whole week.

here's the php code of the registration process,

<?php

include('connection.php');

$name=$_POST['name'];
$username=$_POST['username'];
$password=$_POST['password'];
$password2=$_POST['password2'];


$sql=mysqli_query($conn,"INSERT INTO admin (name,username,password,password2) VALUES ('$name','$username','$password','$password2')");

if($sql == TRUE)
{
    echo '<script language="javascript">';
    echo 'alert("Register Successfully");';
    echo 'window.location.href="index_admin.php";';
    echo'</script>';
}

else
{
    echo "Error: ".$sql."<br>".$conn -> error;
}
    $conn -> close();


?>

Why would you wanna do that? you gonna limit registration until when? — Masivuye Cokile, Dec 06 '18 at 12:10
You are _wide open_ to SQL injection attacks. Use parameterized prepared statements instead of injecting unescaped user data into your query like that — M. Eriksson, Dec 06 '18 at 12:12
Well then you will have to `COUNT` the current rows in the `admin` table before allowing a new user to register. ___Bit odd that an ADMIN can register themselves though___ — RiggsFolly, Dec 06 '18 at 12:13
You should also _never_ store passwords in plain text. You should _only_ store password hashes generated with PHP's built in `password_hash()` and verify the hash with `password_verify()`. I also don't see the point of storing `password2`. Isn't that just to verify that the user have entered the correct password? — M. Eriksson, Dec 06 '18 at 12:14
until it reach 2 users,. i only want just 2 user that can register — Royale Bliss, Dec 06 '18 at 12:14
Before adding do a select count users on your table if they equal to two show message else if less register....... this does not make any sense though — Masivuye Cokile, Dec 06 '18 at 12:18
surely [this one?](https://stackoverflow.com/questions/39758422/mysql-insert-only-if-a-condition-is-true) — Martin, Dec 06 '18 at 13:55

score 0 · Accepted Answer · edited Dec 06 '18 at 13:51

0

Answer to your question: before inserting into database do a select count like

select count(*) from admin;

if returned rows are <=1 , do insert , otherwise do not insert.

you can also use different query and PHP mysqli_num_rows()

this might Help you PHP Manual

Now. advise. you are not checking several thing before inserting

always check data received should not be empty
always check duplicate username
always check escape characters

so please think what else can break your code.

edited Dec 06 '18 at 13:51

Martin

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answered Dec 06 '18 at 12:18

Ali

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_if returned rows are <=2?_ `<=1` surely to allow only 2 – RiggsFolly Dec 06 '18 at 12:22
totally agree with RiggsFolly, but i was wring explain and not coding, some bad pseudocode :-) – Ali Dec 06 '18 at 12:30
can you please make it more details about the code, how can i limit the user registration? – Royale Bliss Dec 07 '18 at 12:23

score -1 · Answer 2 · edited Dec 06 '18 at 12:58

-1

If I understand your question correctly.....

You should do a query to select everything from your table then do a count of the result.

Then wrap your entire query inside an if() condition.

if($num_results < 2){
    // your code here
}else{
    // there are already two entries in your db
}

edited Dec 06 '18 at 12:58

Peter

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answered Dec 06 '18 at 12:18

Paddy Hallihan

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why would you select everything for simple query.. just count the userid in the db – Masivuye Cokile Dec 06 '18 at 12:19
depends on the connection to the DB, should be using prepared statements but either `mysqli_num_rows()` or `count()` doesn't matter just whatever way you want to get the `$num_results` variable – Paddy Hallihan Dec 06 '18 at 12:30
1

But surely efficiency always matters – RiggsFolly Dec 06 '18 at 12:35
yeah you're right... only two results though – Paddy Hallihan Dec 06 '18 at 12:39

How to limit user registration

2 Answers2