Foreign key constraint on sub-column of composite-type column

On 20 October 2012 06:57, David Lee <davidomundo@gmail.com> wrote:

I was trying to create foreign key constraints on a sub-column of a composite-type column, but couldn't find a way to do it. After asking around on IRC, it seems like this isn't supported in PostgreSQL.

I wanted to do something like:

create type profile as (account_id integer);

create table users (profile profile);

alter table users add constraint account_fk foreign key ((profile).account_id) references accounts;

Would this be a viable feature request?

We're currently trying to add FKs for arrays. Other more complex
constraints make a lot of sense, just as exclusion constraints make
sense for single table constraints.

I think its worth logging so we know somebody actually wants this,
thanks for your input.

--
Simon Riggs http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services