Re: foreign keys to foreign tables

Rick Otten <rottenwindfish(at)gmail(dot)com> writes:
> 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.

What's going to happen when the foreign server decides to delete some rows
from its table?

regards, tom lane