Top 3 values per group query MS Access - sql

Question

im new to MS access, and im trying to make a query that will pull up the top 3 people in 3 different categories in terms of points, i.e the desired outcome is :
Child's name | Membership Type | Total Points
=============================================
Jon Snow | Senior | 12
Hodor | Senior | 13
Bran Stark | Senior | 67
Cersei | Intermediate | 14
Joffery | Intermediate | 19
Ramsay Bolton| Intermediate | 25
Wun-Wun | Junior | 14
Arya Stark | Junior | 64
Ned Stark | Junior | 125
Ive found bits of code like this, which i /think/ does it,
SELECT StudentID, TestID, TestScore
FROM MyTable t
WHERE TestID IN
(
SELECT TOP 3 TestID
FROM MyTable
WHERE StudentID = t.StudentID
ORDER BY TestScore DESC, TestID
)
ORDER BY StudentID, TestScore DESC, TestID;
But i have no idea what this means, let alone how to adapt it to fit my needs.
Does anyone out there have an idea on how to get the desired out come?
EDIT: subbed in version that pulls up a syntax error.
SELECT [Members.Childs Name], [Members.Membership Type], [Results.Total Points]
FROM
(SELECT [Members.Childs Name], [Members.Membership Type], [Results.Total Points],
(SELECT Count(*) FROM [Results], [Members] sub
WHERE sub.Total Points <= Results.Total Points
AND sub.Membership Type = Members.Membership Type) As GroupRank
FROM Members, Results t) As main
WHERE main.GroupRank <= 3
ORDER BY [main.Membership Type],[main.Total Points DESC]
P.S Unrelated, but The finale was amazing :)

Answer 1

Consider a correlated sub query that calculates an ordinal rank count which you can then use as a derived table to select top three:
SELECT main.StudentID, main.MembershipType, main.TestScore
FROM
(SELECT t.StudentID, t.MembershipType, t.TestScore,
(SELECT Count(*) FROM MyTable sub
WHERE sub.TestScore >= t.TestScore
AND sub.MembershipType = t.MembershipType) As GroupRank
FROM MyTable t) As main
WHERE main.GroupRank <= 3
ORDER BY main.MembershipType, main.TestScore DESC
To explain specifically, GroupRank is calculated from a subquery (nested select in column section) that ranks TestScores for each MembershipType of outer query. However, this is not enough as you will want to use this calculated GroupRank to pick top three. So nest entire query inside a FROM clause which is known as a derived table as you created an implicit table to return another resultset. This final resultset filters for top 3 and then orders TestScores for each Membership.
In MS Access, you can save entire FROM clause query as its own stored query and then use that query to filter for top three:
SELECT g.StudentID, g.MembershipType, g.TestScore
FROM GroupRankQuery g
WHERE g.GroupRank <= 3
ORDER BY g.MembershipType, g.TestScore DESC
For multiple tables, use table aliases to help which temporarily renames table sources for easier referencing:
SELECT main.[Childs Name], main.[Membership Type], main.[Total Points]
FROM
(SELECT m.[Childs Name], m.[Membership Type], r.[Total Points],
(SELECT Count(*) FROM [Results] subR
INNER JOIN [Members] subM ON subR.StudentID = subM.StudentID
WHERE subR.[Total Points] >= r.[Total Points]
AND subM.[Membership Type] = m.[Membership Type]) As GroupRank
FROM Results r
INNER JOIN Members m ON r.StudentID = m.StudentID) As main
WHERE main.GroupRank <= 3
ORDER BY main.[Membership Type], main.[Total Points] DESC