unique troubles

[morrisoner]

i have a table of users. one field is called username and is a text type. i need it to be unique but whenever it try it says there an error with something like

"field used in key context without key length"

wat can i do to fix this?

[John_Canyon]

You need to make this field a "VARCHAR" field.

I would suggest choosing a limit of characters for a username.

IE.

ALTER TABLE test
ADD username VARCHAR (40),
ADD UNIQUE (username);