jian he <jian.universal...@gmail.com> 于2024年4月11日周四 14:40写道：
> On Wed, Apr 10, 2024 at 2:10 PM jian he <jian.universal...@gmail.com> > wrote: > > > > DROP TABLE if exists notnull_tbl2; > > CREATE TABLE notnull_tbl2 (c0 int generated by default as IDENTITY, c1 > int); > > ALTER TABLE notnull_tbl2 ADD CONSTRAINT Q PRIMARY KEY(c0, c1); > > ALTER TABLE notnull_tbl2 DROP CONSTRAINT notnull_tbl2_c0_not_null; > > ALTER TABLE notnull_tbl2 DROP c1; > > \d notnull_tbl2 > > > ALTER TABLE notnull_tbl2 DROP CONSTRAINT notnull_tbl2_c0_not_null; > per above sequence execution order, this should error out? > > otherwise which "not null" (attribute|constraint) to anchor "generated > by default as identity" not null property? > "DROP c1" will drop the not null property for "c0" and "c1". > if "DROP CONSTRAINT notnull_tbl2_c0_not_nul" not error out, then > " ALTER TABLE notnull_tbl2 DROP c1;" > should either error out > or transform "c0" from "c0 int generated by default as identity" > to > "c0 int" > > I try above case on MASTER and MASTER with Alvaro V2 patch, and all work correctly. \d+ notnull_tbl2 will see not-null of "c0". > > On Thu, Apr 11, 2024 at 1:23 AM Alvaro Herrera <alvhe...@alvh.no-ip.org> > wrote: > > > > On 2024-Apr-10, Alvaro Herrera wrote: > > > > > One thing missing here is pg_dump support. If you just dump this > table, > > > it'll end up with no constraint at all. That's obviously bad, so I > > > propose we have pg_dump add a regular NOT NULL constraint for those, to > > > avoid perpetuating the weird situation further. > > > > Here's another crude patchset, this time including the pg_dump aspect. > > > > +DROP TABLE notnull_tbl1; > +-- make sure attnotnull is reset correctly when a PK is dropped indirectly > +CREATE TABLE notnull_tbl1 (c0 int, c1 int, PRIMARY KEY (c0, c1)); > +ALTER TABLE notnull_tbl1 DROP c1; > +\d+ notnull_tbl1 > + Table "public.notnull_tbl1" > + Column | Type | Collation | Nullable | Default | Storage | Stats > target | Description > > +--------+---------+-----------+----------+---------+---------+--------------+------------- > + c0 | integer | | not null | | plain | > | > + > > this is not what we expected? > "not null" for "c0" now should be false? > am I missing something? > Yeah, now this is expected behavior. Users can drop manually not-null of "c0" if they want, and no error reporte. -- Tender Wang OpenPie: https://en.openpie.com/
