Re: Catalog domain not-null constraints

On 21.03.24 12:23, Peter Eisentraut wrote:
>> All the examples in the tests append "value" to this, presumably by
>> analogy with CHECK constraints, but it looks as though anything works,
>> and is simply ignored:
>>
>> ALTER DOMAIN d ADD CONSTRAINT nn NOT NULL xxx; -- works
>>
>> That doesn't seem particularly satisfactory. I think it should not
>> require (and reject) a column name after "NOT NULL".
>
> Hmm.  CREATE DOMAIN uses column constraint syntax, but ALTER DOMAIN uses
> table constraint syntax.  As long as you are only dealing with CHECK
> constraints, there is no difference, but it shows up when using NOT NULL
> constraint syntax.  I agree that this is unsatisfactory.  Attached is a
> patch to try to sort this out.

After studying this a bit more, I think moving forward in this direction
is the best way. Attached is a new patch version, mainly with a more
elaborate commit message. This patch makes the not-null constraint
syntax consistent between CREATE DOMAIN and ALTER DOMAIN, and also makes
the respective documentation correct.

(Note that, as I show in the commit message, commit e5da0fe3c22 had in
passing fixed a couple of bugs in CREATE and ALTER DOMAIN, so just
reverting that commit wouldn't be a complete solution.)