2017-03-20 13:27 GMT+13:00 Melvin Davidson <melvin6...@gmail.com>: > > > On Sun, Mar 19, 2017 at 8:16 PM, Patrick B <patrickbake...@gmail.com> > wrote: > >> 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! >> >> > Why just "maybe"? Since there can only be three valid answers, why not FK > for all three? > > -- >
I was able to get what I needed this way: create table testing_fk_conditional_1 ( > id serial NOT NULL PRIMARY KEY, > account_id bigint, > user_id bigint, > type_note integer NOT NULL, > CHECK (type_note = 100 AND user_id IS NOT NULL OR type_note = 200 AND > account_id IS NOT NULL) > );
