Question

Pretty simple, however, I’ve yet to find a real straight and appropriate solution;

I’ve currently got my own function that creates a random string, by running two mt_rand() functions from 1 to maximum integers, then wrapping the results in two dechex() functions, and concatenating them into a single string.

I haven’t done the stats on it, but, the chances of two of these strings being the same is pretty low.

However, I’ll obviously need a backup solution which is why I want to perform a query against a database, and see if it exists as an entry, and if it does, re-invoke my own function to create a random string, query again, and loop until a non-existent string is found.

I’ve had a look at a ton of forum threads, and a few SO questions, but have yet to found a concise answer.

Any help would be greatly appreciated, thanks!

Answer 1

You need a recursive function. Something like:

function makeString() {

    // Create our random string
    $string = "";
    $characters = array('a', 'b', 'c', 'd');

    for ($i = 0; $i < 4; $i++) {

        $string .= $characters[mt_rand(0, 4)];
    }

    $query = "SELECT COUNT(*)
    FROM myTable
    WHERE string = '{$string}'";

    $result = mysql_query($query);
    $row = mysql_fetch_assoc($result);

    if ($row['COUNT(*)'] > 0) { // if it already exists, do it again

        $string = makeString();
    }

    return $string;
}