Search Postgresql Archives

Bringing other columns along with a GROUP BY clause

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Greetings!  

I've run into this problem a few times.  There must be a solution, but I
don't know what it is.

I have a table that has three interesting columns:  coil_id, charge, and
coldspot_time.  A charge can have several coils, so there are several
records with differing coil_ids but the same charge.  I want a list of
the coils whose coldspot_times are the largest for their charge.  I can
easily get a list of the maximum coldspot times for each charge:

Select charge, max(coldspot_time) 
>From inventory
Group by charge

But how do I find out what coil has the maximum coldspot time?  

Select coil_id, charge, max(coldspot_time) 
>From inventory
Group by charge

Doesn't work because SQL can't read my mind well enough to know which of
the four coil_ids in the given charge is the one I want.  

Thank you very much!

RobR

-- 
Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Postgresql Jobs]     [Postgresql Admin]     [Postgresql Performance]     [Linux Clusters]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Postgresql & PHP]     [Yosemite]
  Powered by Linux