[QUESTIONS] ORDER BY and nulls (fwd)

Started by Bruce Momjianabout 28 years ago2 messages
#1Bruce Momjian
maillist@candle.pha.pa.us

Is this fixed yet?

Forwarded message:

I seem to recall that someone here said that because of the way comparisons
are done, in an ORDER-BY query, the NULLs will always come up last.

It seems to have another effect, too: if I do a SELECT ... ORDER BY
col1,col2 - and the col1 attribute has nulls, the rows with the nulls don't
get sorted at all.

Apparently, this is because the rows which have NULL in the col1 attribute
are not considered to have an equal value in col1, which is the requirement
for sorting on col2 - or am I missing something here?

Herouth

--
Bruce Momjian
maillist@candle.pha.pa.us

#2Vadim B. Mikheev
vadim@sable.krasnoyarsk.su
In reply to: Bruce Momjian (#1)
Re: [HACKERS] [QUESTIONS] ORDER BY and nulls (fwd)

Bruce Momjian wrote:

Is this fixed yet?

Forwarded message:

I seem to recall that someone here said that because of the way comparisons
are done, in an ORDER-BY query, the NULLs will always come up last.

It seems to have another effect, too: if I do a SELECT ... ORDER BY
col1,col2 - and the col1 attribute has nulls, the rows with the nulls don't
get sorted at all.

Apparently, this is because the rows which have NULL in the col1 attribute
are not considered to have an equal value in col1, which is the requirement
for sorting on col2 - or am I missing something here?

I hope to fix this after Feb 1 (seems easy to do).

Vadim