How can I loop this?

[pneudralics]

Let's say for some reason my md5 string is in the database. How can I repeat md5ing strings until one is not found?

 

<?php
$string = md5($_POST['string']);

if (isset($_POST['submit'])) {
$query = "SELECT * FROM table WHERE string = '$string' LIMIT 1";

if ($result = mysql_query($query)) {
$row = mysql_num_rows ($result);
	if ($row = 0) {
	//insert to database
	}
	else {
	//Repeat md5 string until none is found in database
	}
}	
}
?>

[smerny]

i don't really understand what you are trying to do

[pneudralics]

If the posted string that just got hashed with md5 is already in the database I want to be able to repeat the hashing process until none is found in the database. Then I will allow it to insert into the database.

[smerny]

what is the point? you wouldn't be able to compare that string to it later

 

do you want to be able to compare this string later? what is the reason you don't want the same hash to exist more than once? what are you planning to do with it?

[pneudralics]

Yes I do want to be able to compare it later. Later on I want to be able to add uploaded hashed image names to the database. I don't want the same ones to exist.

[PFMaBiSmAd]

In your previous thread on this, someone already mentioned how you could use a unique key -

 

if you are using mysql, and the random string is a key, you can use INSERT IGNORE  or INSERT...ON DUPLICATE UPDATE queries.