Let's say I'm saving users in a database and I want each user to have a unique random ID (this isn't actually the case, just a simpler example). When I INSERT the user, is there a way to insert a unique random ID?
I know I can easily just do an auto-increment column so that each row would have a unique integer, but I need a random number for this system specifically.
Sample of what my standard insert query for a new user:
INSERT INTO 'Users' VALUES ('RandomID', 'Bleh', 'Bleh2') (random value here, 1, 2)
I was wondering the same and found an interesting answer in this article: use a pre-populated table.
You create before hand a table of n rows with unique random numbers, using any method (for example, by trying to insert random numbers in a UNIQUE field and silently failing when the number isn't unique, until you get the number of rows needed).
Once that table is created you are 100% certain that the numbers in it are unique, and you can simply use them sequentially and discarding them after use (or not).
When using this method you need to have some kind of alert system for when you approach the limit of rows in the pre-populated table, so that you can generate a new set of values anew.