Ranking Aggregate Field in Access Query - sql

Question

I am trying to rank an aggregate field in access but my efforts are in vain with errors based on referencing. I am ranking using a subquery but the problem comes about due to the alias names resulting from performing an average on a field. The code is as below:
SELECT [Exams].[StudentID],
Avg([Exams].[Biology]) AS [AvgBiology],
(SELECT Avg(T.Biology) AS [TAvgBiology],
Count(*)
FROM [Exams] AS T
WHERE T.[TAvgBiology] > [AvgBiology])
+ 1 AS Rank
FROM [Exams]
GROUP BY [Exams].[StudentID]
ORDER BY Avg([Exams].[Biology]) DESC;
Errors that come about state: "You have selected a subquery that can return more than one value blah blah...please use the Exist keyword.. ".
From the code above I think you get the gist of what I am trying to achieve.

Answer 1

Start with the basic GROUP BY query Gordon Linoff suggested to compute the average Biology for each StudentID.
SELECT
e.StudentID,
Avg(e.Biology) AS AvgBiology
FROM Exams AS e
GROUP BY e.StudentID
Save that query as qryAvgBiology and then use it in another query where you compute Rank.
SELECT
q.StudentID,
q.AvgBiology,
(
(
SELECT Count(*)
FROM qryAvgBiology AS q2
WHERE q2.AvgBiology > q.AvgBiology
)
+1
) AS Rank
FROM qryAvgBiology AS q
ORDER BY 3;
For example, if qryAvgBiology returns this result set ...
StudentID AvgBiology
--------- ----------
1 70
2 80
3 90
The ranking query will transform it to this ...
StudentID AvgBiology Rank
--------- ---------- ----
3 90 1
2 80 2
1 70 3

Answer 2

I assume your basic query is:
SELECT e.StudentId Avg(e.Biology) AS AvgBiology
FROM exams as e
GROUP BY e.StudentId;
(Square braces don't help me understand the query at all.)
I think the following will work in Access:
SELECT e.StudentId Avg(e.Biology) AS AvgBiology,
(SELECT 1 + COUNT(*)
FROM (SELECT e.StudentId, Avg(e.Biology) AS AvgBiology
FROM exams as e
GROUP BY e.StudentId
) e2
WHERE e2.AvgBiology > Avg(e.Biology)
) as ranking
FROM exams as e
GROUP BY e.StudentId;