Goran Thyni <goran(at)kirra(dot)net> writes:
> How about this according to SQL standard:
>
> CREATE TABLE x { y integer NULL };
>
> It suppose to mean that NULLs are explicitly allowed in
> this field.
> Is this required by SQL-92?
No, it's not required. This came up before with the examples from
"The Practical SQL Handbook". It would be nice to allow it, but there
was some reason why to do so would be non-trivial, which I forget.
Anyway, it's not in SQL-92.