returning values with a where clause - linq

Question

I have two tables as follows:
ScholarSubject
ScholarSubjectID<pk>
ScholarID
SubjectID
Mark
and
AdmissionReq
SubjectID
DegreeCode
MinumumMark
I'm trying to return everything from a Degree table (with PK degreeID) where the mark for a scholar is less than the minimum mark for admissions. My query is as follows:
public List<object> getDegreeByAPSandRequirements()
{
using (DataLayer.CareerDatabaseEntities context = new DataLayer.CareerDatabaseEntities())
{
return (from Degrees in context.Degrees
join admissions in context.AdmissionReqs on
Degrees.DegreeCode equals admissions.DegreeCode
join subject in context.Subjects on
admissions.SubjectID equals subject.SubjectID
join scholarsubject in context.ScholarSubjects on
subject.SubjectID equals scholarsubject.SubjectID
join scholar in context.Scholars on
scholarsubject.ScholarID equals scholar.ScholarID
where Degrees.APSScore <= scholar.APSScore && admissions.MinimumMark <= scholarsubject.NSC && scholarsubject.SubjectID.Equals(admissions.SubjectID)
select Degrees).Distinct().ToList<object>();
}
}
Everything works, except if I change one of the marks (in ScholarSubject) to a lesser value than the minumum mark (in AdmissionsReq) then it still returns a degree. I want to return a degree if both marks are greater than the minimum requirements and not only one of the marks.
What am I doing wrong? Can someone please help me??

Answer 1

I'm still not sure I understand what you're trying to do - unless you have just one scholar in your database it seems to me you will return a list of all degrees achieved by all scholars. If you don't want this, you need to filter on scholarID in the where clause.
But anyway - in order to get more information I would try to do 2 things.
I would change your query and start it with the scholar not with the degree as this might avoid some duplicates:
from scholar in context.Scholars
join scholarsubject in context.ScholarSubjects on scholar.ScholarID equals scholarsubject.ScholarID
join subject in context.Subjects on scholarsubject.SubjectID equals subject.SubjectID
join admission in context.AdmissionReqs on subject.SubjectID equals admission.SubjectID
join degree in context.Degrees on admission.DegreeCode equals degree.DegreeCode
where degree.APSScore <= scholar.APSScore
&& admission.MinimumMark <= scholarsubject.NSC
//&& scholarsubject.SubjectID.Equals(admission.SubjectID) // you should not need this line as you have the joins in place to assert this
select degree)
.Distinct()
.ToList<object>();
If this produces the same result as your previous query, then I'd change the return type to see what exactly you are getting - replace the last line with this and inspect the collection:
select new {ScholarID = scholar.ScholarID, Degree = degree})
.Distinct()
.ToList();