From: Eddie Cheung <vampyre5@yahoo.com>
To: pgsql-sql@postgresql.org
Subject: Help with query involving aggregation and joining.
Date: Sun, 23 Feb 2003 11:02:27 -0800 (PST)
Message-ID: <20030223190227.21867.qmail@web80401.mail.yahoo.com> (raw)
Hi,
I have not been able to construct an SQL statement for
my task. What seemed like a simple query turned out to
be beyond my capability. Any help will be very much
appreciated.
My requirements involve several large tables. I have
simplied scenario into the follow two fictional tables
which describes the same requirements.
HISTORY
=======
id | courseId | submission
---+-----------+-------------
1 | 101 | 2002-01-20
2 | 102 | 2002-02-17
3 | 104 | 2002-04-30
4 | 102 | 2002-02-22
5 | 104 | 2002-03-15
6 | 104 | 2002-01-21
COURSE
======
id | name
------+-----------
101 | Physics
102 | Chemistry
103 | Biology
104 | Maths
105 | English
Basically I would like to display the latest
submission for each course in a table as shown below,
order by name of the courses.
Query Results:
==============
id | courseId | name | submission
---------------------------------------
4 | 102 | Chemisty | 2002-02-22
3 | 104 | Maths | 2002-04-30
1 | 101 | Physics | 2002-01-20
I have tried many different approach but all failed...
Thanks a lot for your help.
Regards,
Eddie
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To: pgsql-sql@postgresql.org
Cc: vampyre5@yahoo.com
Subject: Re: Help with query involving aggregation and joining.
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