Re: Help with query involving aggregation and joining.

Eddie,

> My requirements involve several large tables. I have
> simplied scenario into the follow two fictional tables
> which describes the same requirements.

Keep in mind that a simplified example may not solve your real problem ...

> 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

Easy:

SELECT id, courseid, name, max(submission) as submission
FROM history JOIN courses ON history.courseid = course.id
GROUP BY id, courseid, name
ORDER BY name

And as such, I suspect that your real case is more complicated than the above
...

--
Josh Berkus
Aglio Database Solutions
San Francisco