Question

I’m using the function below to create a unique field that is prefixed with a letter.
Will this cause any problems if its used for transactions with many users?
The scenario is that this function is called inside a loop and if there are many users simultaneously using the system. Will this cause any errors?Is there a better way to do this?I’m using the GLAccountID as foreign key to the other tables.

function getID(){
    global $db;
    $max_gl = $db->get_var("SELECT MAX(GLAccountNumber) FROM sys_glaccount");
    if($max_gl == null){
        $max_gl = 1;
    }else if($max_gl > 0){
        $max_gl = $max_gl + 1;
    }
    return 'GLA'.$max_gl;
}

The table looks something like this, GLAccountNumber is the primary key and I set it to auto-increment.

Answer 1

There are ways to do this, but you shouldn’t really. Seriously. This is heavy and dangerous and the developer after you will cry a bit at night.

Please consider using the accountNumber, and just adding the GLA whenever you retrieve it? This way you have the simple, quick and correctness of the auto-id, and can pretttify it when you want.

Another option is to make it a combined key, with your prefix in one column and the number in the auto-increment, although I don’t see why you should want it.

In the end, if all you do is add three letters, you don’t need to actually do it in the same field 🙂