Re: select & group by

Michael L. Hostbaek wrote:
> I've got a problem selecting some specific data from my table. Imagine
> the following rows:
>
> part | mfg | qty | price | eta
> ---------------------------------------
> TEST1 ABC 10 100 (No ETA, as item is in stock)
> TEST1 ABC 12 120 04/04
> TEST2 CBA 17 10 05/05
> TEST2 CBA 10 20 (No ETA, as item is in stock)
>
>
> I'd like my selection to produce the following result:
>
> part | mfg | qty | qty incoming | highest price | eta
> -------------------------------------------------------------
> TEST1 ABC 10 12 120 04/04
> TEST2 CBA 10 17 20 05/05
>
> Any clues on how to do this ? I kow the group by part, mfg, max(price) -
> but I do not know how to deal with the splitting up qty and stock qty
> and incoming qty.

How about something like:

SELECT
aa.part,
aa.mfg,
aa.qty,
bb.qty AS qty_incoming,
CASE WHEN aa.price > bb.price THEN aa.price ELSE bb.price END AS
highest_price,
aa.eta
FROM
(
SELECT part,mfg,qty,price FROM mytable WHERE eta IS NOT NULL
) aa,
(
SELECT part,mfg,qty,price FROM mytable WHERE eta IS NULL
) bb
WHERE
aa.part = bb.part
AND aa.mfg=bb.mfg
;

This is assuming you only have one row with "eta" set for each
(part,mfg). If not, you'll have to identify which row you want.

--
Richard Huxton
Archonet Ltd