Re: Is this a buggy behavior?

On 3/24/24 08:28, Thiemo Kellner wrote:
> Sure, my example has lots more side effect than silently do the right thing.

I think the point is that it's not really doing anything "silently." You are asking for a PRIMARY KEY constraint on a column, and it's giving it to you. One of the effects (not even really a side-effect) of that request is that the column is then declared NOT NULL.

The reason it doesn't give you a warning is that by the time it would be in a position to, it's forgotten that you explicitly said NULL. It does see that the column in nullable, but that in itself isn't worth emitting a warning over, since you are explicitly telling it that now the column shouldn't be null. It wouldn't make much more sense to emit a warning there than it would be in this situation:

CREATE TABLE t (i int NULL);
ALTER TABLE t ALTER i SET NOT NULL;

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com