Jeremy Finzel <finzelj@gmail.com> writes:
> I'm not sure if this can be considered a bug or not, but it is perhaps
> unexpected. I found that when using a view that is simply select * from
> table, then doing INSERT ... ON CONFLICT ON CONSTRAINT constraint_name on
> that view, it does not find the constraint and errors out. But it does
> find the constraint if one lists the columns instead.
I'm confused by this report. The view wouldn't have any constraints,
and experimenting shows that the parser won't let you name a
constraint of the underlying table here. So would you provide a
concrete example of what you're talking about?
regards, tom lane
Apologies for the lack of clarity. Here is a simple example of what I mean:
test=# CREATE TEMP TABLE foo (id int primary key);
CREATE TABLE
test=# \d foo
Table "pg_temp_4.foo"
Column | Type | Collation | Nullable | Default
--------+---------+-----------+----------+---------
id | integer | | not null |
Indexes:
"foo_pkey" PRIMARY KEY, btree (id)
test=# CREATE VIEW bar AS SELECT * FROM foo;
NOTICE: view "bar" will be a temporary view
CREATE VIEW
test=# INSERT INTO foo (id)
test-# VALUES (1)
test-# ON CONFLICT ON CONSTRAINT foo_pkey
test-# DO NOTHING;
INSERT 0 1
test=# INSERT INTO foo (id)
VALUES (1)
ON CONFLICT ON CONSTRAINT foo_pkey
DO NOTHING;
INSERT 0 0
test=# INSERT INTO foo (id)
VALUES (1)
ON CONFLICT ON CONSTRAINT foo_pkey
DO NOTHING;
INSERT 0 0
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 point of interest for us is that we frequently preserve a table's "public API" by instead swapping out a table for a view as above, in order for instance to rebuild a table behind the scenes without breaking table usage. Above case is a rare example where that doesn't work, and which in any case I advise (as does the docs) that they do not use on conflict on constraint, but rather to list the field names instead.
Thanks,
Jeremy