foreign keys to foreign tables

Hello pgsql-general,

I'd like to set up a foreign key constraint to a foreign table from a local
table.

ie, I have a column in a local table that I'd like to ensure has a value in
the foreign table.

alter mytable
add column some_column_id uuid references myforeigntable(some_column_id)
;

Unfortunately I get a "not a table" error when I try this.

ERROR: referenced relation "myforeigntable" is not a table

I'm thinking I'll have to write a function that checks for existance of the
ids in the foreign table, and then put a CHECK constraint on using that
function, but I thought I'd as first if there was a better way.

Thanks.

--
Rick Otten
rottenwindfish(at)gmail(dot)com