never ending loop : fatal error

Question

my code-

function create_id()
{  
    //global $myusername;  
    $part1 = substr("Piyush", 0, -4);  
    $part2 = rand (99,99999);  
    $part3 = date("s");  
    return $part1.$part2.$part3;  
}

echo create_id();  //this is printing fine.

function isUniqueUserID($userIDToCheck)    
{
    $sqlcheck = "Select * FROM ruser WHERE userId='$userIDToCheck';";    
    $resource = mysql_query($sqlcheck)or die(mysql_error());   
    $count = mysql_fetch_assoc($resource);  
    if( count($count) > 0)  
    {return false;}  

    return true;  
}


$userIDVerifiedUnique = false;  
while(! $userIDVerifiedUnique )  
{  
    $userIDToCheck = create_id();  
    $userIDVerifiedUnique = isUniqueUserID($userIDToCheck );  
}

loop is just going on and on from while loop to function IsUniqueUser() and vice versa.????

Answer 1

First, try changing your isUniqueUserID() function to this

function isUniqueUserID($userIDToCheck)
{

$userIDToCheck = mysql_real_escape_string($userIDToCheck); //prevent SQL injection

$sqlcheck = "Select userId FROM ruser WHERE userId='$userIDToCheck';";
$resource = mysql_query($sqlcheck)or die(mysql_error());
$count = mysql_num_rows($resource);

return ($count > 0) ? false : true;

There's no point in returning an associative array just to count the number of rows in it. And there's no point in doing a SELECT * when counting just do SELECT userId since that's all you're concerned with.

I don't see any other reason that isUniqueUserID() would return false unless your ruser table has every possible ID.

Answer 2

If there are no rows returned from the MySQL query (i.e. the $userIDToCheck is not in the table, it is unique) then mysql_fetch_assoc will return FALSE. When that happens, count(FALSE) returns 1 (one)! Since that value is greater than zero the function returns FALSE.

In short, if there is a row returned (the string is not unique) your isUniqueUserID function returns FALSE; if there is no row returned (the string is unique) it still returns FALSE.

---

A simple, new, function to check on the database table could look something like the following...

function isUniqueUserID($userIDToCheck)
{
    $userIDToCheck = mysql_real_escape_string($userIDToCheck); // Assume not already escaped
    $sqlcheck = "SELECT 1 FROM ruser WHERE userId='$userIDToCheck' LIMIT 1";    
    $resource = mysql_query($sqlcheck) or die(mysql_error());
    return (bool) mysql_num_rows($resource);  
}