Daniel CAUNE wrote:
SELECT aid, cat
FROM table, (
SELECT aid, max(weight) as weight
FROM table
GROUP BY aid) AS tablemaxweight
WHERE table.aid = tablemaxweight.aid
AND table.weight = tablemaxweight.aid;
There is a limit case you don't specify how to deal with, when two or more
categories have the same maximum weight. The query I wrote retrieves all the
categories that have the maximum weight, but perhaps you just want one per aid.
Yes, this will introduce duplicates. Yet it is not too difficult to
select only one for each aid from the results. Thank you!
Weimao
--
Daniel
--
All best,
Weimao
Weimao Ke
Indiana University Bloomington
School of Library and Information Science
http://ella.slis.indiana.edu/~wke
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