Does this small piece of code seem ok?

Especially compared to all of the discussion about randomness, this is a minor item, but I would generally forego the extra variable and do something like this:

PHP Code:

$check = 0;
while ($check === 0) {
    $code = get_random_string();
    $check = $this->db->where('guest_code', $code)->count_all_results('guests');
} 


or

PHP Code:

do {
    $code = get_random_string();
    $check = $this->db->where('guest_code', $code)->count_all_results('guests');
} while ($check === 0); 


It has been awhile but I just had to reply on this.

Shouldn't it be

PHP Code:

while( $check === 1 ) 


Because no match means $check remains 0 and the cycle is run again right? But we only want the cycle to rerun if a match was found setting $check = 1;