On Wed, 2024-07-03 at 11:42 +0200, Navrátil, Ondřej wrote:
> On a side note, I tested similar behavior in Oracle databases, and for them, something like
> select testtype(null, null) is null; -- returns 0 (false)
> select testtype(null, null) is not null; -- returns 1 (true)
> ...and as far as I could test, in Oracle the IS NULL and IS NOT NULL operators are truly dual
That only goes to say that Oracle is not very standard compliant, but
I wouldn't expect anything else from a system where '' IS NULL.
Yours,
Laurenz Albe