检查重复的SQL或PHP？

Question

I have a field in my users database, a 6 digit number that is generated upon registration. I use mt_rand(100000, 999999) to generate the numbers.

Now to the question, to make sure no one gets the same number I need to either make the field UNIQUE (which i think seems the best) instead of some PHP code. Maybe theres some other way I don't know. The question is, whats the best way to do this?

Answer 1

You can do this way using PHP.

First give a unique constraint to the field.

if (mysqli_errno() == 2027)
    mysqli_query("INSERT INTO ... {mt_rand()}");

So, once you insert a duplicate value, it gives out an error code 2027, saying duplicate. You can resubmit the query.