Re: UPSERT on view does not find constraint by name

Jeremy Finzel <finzelj@gmail.com> writes:
> test=# CREATE TEMP TABLE foo (id int primary key);
> CREATE TABLE
> test=# CREATE VIEW bar AS SELECT * FROM foo;
> NOTICE:  view "bar" will be a temporary view
> CREATE VIEW
> ...
> test=# INSERT INTO bar (id)
> VALUES (1)
> ON CONFLICT ON CONSTRAINT foo_pkey
> DO NOTHING;
> ERROR:  constraint "foo_pkey" for table "bar" does not exist
> test=# INSERT INTO bar (id)
> VALUES (1)
> ON CONFLICT (id)
> DO NOTHING;
> INSERT 0 0

> Of interest are the last 2 statements above.  ON CONFLICT on the constraint
> name does not work, but it does work by field name.  I'm not saying it
> *should* work both ways, but I'm more wondering if this is
> known/expected/desired behavior.

The first case looks perfectly normal to me: there is no "foo_pkey"
constraint associated with the "bar" view.  It is interesting that
the second case drills down to find there's an underlying constraint,
but that seems like a bit of a hack :-(.

Poking at it a little more closely, it seems like the first case
involves a parse-time constraint lookup, while the second case
postpones the lookup to plan time, and so the second case works
because the view has already been expanded into a direct reference
to the underlying table.  Maybe it wasn't good to do those cases
differently.  I can't get too excited about it though.

            regards, tom lane