I’m working on a high school grading system.
At my school, grades can be changed by reworking problems and I store these changes with dates.
I have a function that properly returns averages because the most recent grade is flagged with a “current” field with a value of ‘1’. I’d like to make the function capable of returning the most recent grade with respect to a date in the past. I’m making a graph of how their average has changed over time.
What I’d like to do is something like this:
select sum(grades.points)
from grades
where date < 'thedate'
order by date DESC
group by assignmentID
I can’t use sum and group by. It errors…
The best I can think of is to do a sub-select. Any other thoughts?
GROUP BY has to come before ORDER BY:
SELECT SUM(g.points)
FROM GRADES g
WHERE g.date < 'thedate'
GROUP BY g.assignmentid
ORDER BY g.date DESC
Try this:
SELECT cat_name, SUM(amount) AS total_amount
FROM table
GROUP BY cat_name
2