| From: | Weimao Ke <wke(at)indiana(dot)edu> |
|---|---|
| To: | pgsql-sql(at)postgresql(dot)org |
| Subject: | pgsql aggregate: conditional max |
| Date: | 2006-03-12 05:09:48 |
| Message-ID: | 4413AD1C.9050604@indiana.edu |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-sql |
Hi,
I need a special aggregation function. For instance, given the following
table data:
aid | cat | weight
----------+---------+---------
a1 | Drama | 1
a1 | Romance | 6
a1 | Short | 1
a1 | Other | 7
a2 | Comedy | 1
a2 | Drama | 2
a3 | Drama | 1
a3 | Adult | 2
a3 | Comedy | 1
a3 | Other | 1
I want to group by "aid" and choose the category (i.e., "cat") with the
largest "weight":
aid | max_weighted_cat
----+---------------------
a1 | Other
a2 | Drama
a3 | Adult
Any ideas? Thank you! :)
--
All best,
Weimao
Weimao Ke
Indiana University Bloomington
School of Library and Information Science
http://ella.slis.indiana.edu/~wke
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Jeffrey Melloy | 2006-03-12 05:34:57 | Re: pgsql aggregate: conditional max |
| Previous Message | Christopher Browne | 2006-03-11 17:00:27 | Re: Merging rows into one result? |