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?
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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) );