Comments on: Complex sort for SQL Query?

By: TomLiotta

TomLiotta — Wed, 10 Oct 2012 23:15:13 +0000

I’m thinking maybe the OP confused terms. Hard to tell without a response. — Tom

By: carlosdl

carlosdl — Wed, 10 Oct 2012 23:08:16 +0000

Oh, I just realised that maybe I’m confusing terms. That one is not the oldest, but the newest date.

By: carlosdl

carlosdl — Wed, 10 Oct 2012 23:03:38 +0000

This would be the record with the oldest date (Name4, 2, 9/3/2012), and I think the format being used is d/m/yyyy.

The text formatting in the question doesn’t help much.

By: TomLiotta

TomLiotta — Wed, 10 Oct 2012 22:11:01 +0000

Actually, the oldest date is in the first group, which happens to be for the identifier ’2′.

What am I missing? The oldest date I can see is “1/2/2012″, for identifier ’3′, which should be either 1 Feb 2012 or Jan 2 2012. The oldest date for identifier ’2′ is “1/3/2012″. Whichever date format is used, “1/2/2012″ is an earlier (oldest) date. Isn’t it? (Maybe I’m too tired lately.)

Tom

By: carlosdl

carlosdl — Wed, 10 Oct 2012 21:50:06 +0000

And the simplest one, using an analytic MAX:

SELECT name,identifier,”DATE”,MAX(“DATE”) OVER (PARTITION BY identifier) md
FROM your_table
ORDER BY md DESC,identifier,”DATE”;

By: carlosdl

carlosdl — Wed, 10 Oct 2012 21:26:37 +0000

On recent Oracle versions, this should also work:

WITH t AS (
SELECT identifier,max(“DATE”) max_date
FROM your_table GROUP BY identifier
)
SELECT yt.name,yt.identifier,yt.”DATE”
FROM your_table yt JOIN t
on yt.identifier=t.identifier
ORDER BY t.max_date DESC,yt.identifier,yt.”DATE”;

By: carlosdl

carlosdl — Wed, 10 Oct 2012 21:20:05 +0000

“…dates are ordered; but the ‘oldest’ date isn’t in the first group — it’s in the second group“

Actually, the oldest date is in the first group, which happens to be for the identifier ’2′.

If I understand correctly, something like this should do the trick:

SELECT name,identifier,”DATE”,(select MAX(“DATE”) FROM your_table WHERE identifier = yt.identifier)
from your_table yt
ORDER BY 4 desc,2,3;

I think something like this is what Todd was suggesting too.

By: ToddN2000

ToddN2000 — Wed, 10 Oct 2012 20:07:14 +0000

If I understand how you are looking to sort this, I don’t think you can do it with one table. It sounds like you want them sorted by date to find the order for your groups then sort all related group detail data by date within that group. You might try and create an alias table that is a summary of groups in date order. Then use this table in group/date order to get the full detail in date sequence.

By: TomLiotta

TomLiotta — Tue, 09 Oct 2012 23:21:15 +0000

What does the “identifier” identify? It doesn’t seem to identify a name nor a date. It would seem to be an “identifier” for some entity that is defined in a different table.

Your “example” of how you want it to work doesn’t seem to have any identifiable sequence. It does seem to be ‘grouped by’ the “identifier” but the “identifier” has no meaningful ordering. Within each group, dates are ordered; but the ‘oldest’ date isn’t in the first group — it’s in the second group.

More info is needed about how you want this to work. Perhaps an entirely new set of example values might even be helpful.

Tom