check if username exists and generate new username if it does PHP - php

Question

I am trying to write a simple function that checks if a username exists in the db and if so to call another function to generate a new username. My code seems to fall over though:
Username Function:-
$user1=create_username($fname, $company);
function create_username($surname, $company){
//$name_method=str_replace(" ", "", $surname);
$name_method=$surname.$forename;
$company_name_method=str_replace(" ", "", $company);
if(strlen($name_method)<=5)
{
$addition=rand(11,99);
$first=$addition.$name_method;
}
else
{
$first=substr($name_method,0,5);
}
if(strlen($company_name_method)<=5)
{
$addition2=rand(11,99);
$second=$addition2.$company_name_method;
}
else
{
$second=substr($company_name_method,0,5);
}
$middle=rand(100,1000);
$username=$first.$middle.$second;
return($username);
}
Check Username Function:
check_user($user1, $dbc, $fname, $company);
function check_user($user1, $dbc, $surname, $company){
$check_username="SELECT username FROM is_user_db WHERE username='$user1'";
$resultx=mysqli_query($dbc, $check_username) or die("Could not check username");
$num_rows=mysqli_num_rows($resultx);
if($num_rows>0)
{
$user1=create_username($fname, $company);
check_user($user1, $dbc, $fname, $company);
}
else
{
return($user1);
}
}
It just seems to return the original username.

Answer 1

You probably need to re-factor your code a little. Write out the steps on paper; that helps me. So far, I can see:
You want to check a username is unique on form submission
If it's not, generate a new username
So, check the username when your form is POSTed:
<?php
if (isset($_POST['submit'])) {
if (username_unique($_POST['username'])) {
// carry on processing form
}
else {
$suggested_username = suggest_username($_POST['username']);
// display form, with new suggested username?
}
}
And then write your functions:
<?php
// following on from code from above
function check_username($username) {
// get database connection (I use PDO)
$sql = "SELECT COUNT(*) AS count FROM users_tbl WHERE username = ?";
$stmt = $pdo->prepare($sql);
$stmt->execute(array($username));
$row = $stmt->fetchObject();
return ($row->count > 0); // if 'count' is more than 0, username already exists
}
function suggest_username($username) {
// take username, and add some random letters and numbers on the end
return $username . uniqid();
}
Hopefully this will help. Obviously it'll need some modification to work in your set-up, but this is the general flow you'll need.