MySQL: Can I add an ENUM value later?

hydraMax · 05-08-2011, 04:22 AM

Say I create a MySQL table with a ENUM column with the possible values BOOK, DVD, and CASSETTE. And then two years later I decide I want to add another possible value (say, ISOLINEAR CHIP :-). This won't be a problem, right? I got the impression from an on-line post that I could use ALTER TABLE to do this and it wouldn't be a problem. But I wanted to get a second opinion because obviously I don't want to come back two years later and run into some major issue.

paulsm4 · 05-08-2011, 05:21 AM

Hi -

I would strongly discourage you from using "enum's": use codes (1, 2, 3, etc) or strings ('BOOK', 'DVD', etc) instead. This, of course, is the exact OPPOSITE of what you'd want to do in a programming language (like C++ or Java), but it's actually sound advice for SQL. Especially if you ever want to use this data elsewhere, besides a MySQL database.

ANYWAY - to answer your question: Yes, you CAN add (or change) mySql enums post facto. Yes, you'd do it with "alter table" syntax. But you might encounter problems:

http://stackoverflow.com/questions/1...olumn-in-mysql