Question

I’m trying to create a function that, when run, creates numerical ID, checks to see if that ID exists in the DB and if it does exists then create another ID and check again until it has a unique ID. I’m stuck on how to loop in the functions withing a function

function createUniqueID() {

function buildUnique() {
    $uniqueID = rand(100000000000,999999999999);
    return $uniqueID;
}

function compareWithDB($uniqueID) {
    $s = "SELECT id FROM table WHERE id='{$uniqueID}'";
    $r = mysql_query($s);
    return $r;
}

function countDBRows($r) {
    if(mysql_num_rows($r) >0){
        $f = false; // found   
    } else{
        $f = true;
    }
}

$uniqueID = buildUnique();
$r = compareWithDB($uniqueID);
$f = countDBRows($r);

if (!$f) {
    $uniqueID = 'nope';
}

return $uniqueID;

}

Answer 1

You’re much better off to call MySQL’s UUID() function, and store & return the value of that, unless the value absolutely must be numeric.

SELECT UUID();