On Mon, Mar 25, 2024 at 9:49 AM Christophe Pettus <x...@thebuild.com> wrote:
> > > > On Mar 25, 2024, at 02:50, Thiemo Kellner <thi...@gelassene-pferde.biz> > wrote: > > My bad. I was under the impression that the create table statement was > an atomic process/transaction with all its bells and whistles for > constraints and keys, instead of a succession of alter statements. > > That may be a bit judgmental. :-) It's not a series of ALTER statements, > really. The basic issue is that the parser throws away a bare NULL very > early in the process, so it is not available to consult at the point that > PostgreSQL is creating the constraint. The underlying implementation of > the actual table creation isn't the issue here. > > There seems to be general consensus that: > > 1. It would be handy to have a warning in the particular case that NULL is > specified, however, > 2. It would be undesirable to have a warning in the case where no NULL at > all is specified, which means, > 3. The presence of an existing bare NULL would have to be retained through > the whole process, which is, > 4. Not trivial. > > The reason the SQL standard is relevant here is that if bare NULL were > part of the standard, that would be an argument for taking the pains. > Since it's not, it's not clear that doing the work to add the warning is > worth the effort. > Such a warning *could* be put in psql*, but is the effort worth the benefit? I don't really think OP's scenario is very common. *People using pgAdmin, pgcli, etc wouldn't see the warning.
