Constraint + where

[Patrick B <patrickbakerbr@xxxxxxxxx>]

Hi guys,

I've got a column 'type_note' on a new table that it's being designed:

type_note varchar(32) NOT NULL;

On that column, there will be three different data:

1. yes

2. no

3. maybe

I wanna create a FK but just when the data on that column is = maybe.

How can I do that? Thanks!