Shay Rojansky <roji@roji.org> writes:
> I can see the PG 13.3 change note about GENERATED ALWAYS AS IDENTITY no
> longer being compatible with an explicit NULL specification. However, it
> seems that GENERATED BY DEFAULT AS IDENTITY also is no longer compatible
> with null:
> CREATE TABLE foo
> (
> id INTEGER NULL GENERATED BY DEFAULT AS IDENTITY
> );
> Results in:
> ERROR: conflicting NULL/NOT NULL declarations for column "id" of table
> "foo"
> Is this intended?
GENERATED BY DEFAULT does create a NOT NULL constraint:
regression=# CREATE TABLE foo(id INTEGER GENERATED BY DEFAULT AS IDENTITY);
CREATE TABLE
regression=# \d foo
Table "public.foo"
Column | Type | Collation | Nullable | Default
--------+---------+-----------+----------+----------------------------------
id | integer | | not null | generated by default as identity
so I think the patch is doing what it was intended to. Whether GENERATED
BY DEFAULT *should* be forcing NOT NULL is a separate question, but
AFAIK it always has.
regards, tom lane