Speeding up a linq query - asp.net-mvc

Question

I am trying to replicate the following SQL query with linq. On SQL Server it takes a fraction of a second to run:
select g.reference, count(*)
from isis.dbo.[group] as g inner join
isis.dbo.enrolment as e on g.groupid = e.groupid inner join
isis.dbo.student as s on e.studentid = s.studentid inner join
isis.dbo.progression as p on s.studentid = p.studentid
where p.academicyear = '12/13' and g.istutorgroup = 1
group by reference
In my MVC application I am passing a listing of "TutorGroups" to the view. For each tutor group in the view I need to display various information about them, one item being the number of "Progression" interviews they have had.
I have tried a couple of methods but they both take upwards of 30 secs to run in my MVC application:
<%TTMrequired = tg.Enrolments
.SelectMany(e => e.Student.Progressions
.Where(p => p.TTMChecked == false &&
p.TTMInterview == true &&
p.AcademicYear == year))
.Count(); %>
and
<%TTMrequired = tg.Enrolments
.Where(e => e.Student.Progressions
.Any(p => p.TTMChecked == false &&
p.TTMInterview == true &&
p.AcademicYear == year))
.Count(); %>
Anyone got any suggestions on how I can speed this up? I suspect the problem is me trying to do it a stupid way - it usually is!

Answer 1

You could try doing a Sum of counts instead of a SelectMany:
tg.Enrolments.Sum(e => e.Student.Progressions
.Count(p => p.TTMChecked == false &&
p.TTMInterview == true &&
p.AcademicYear == year)
);

Answer 2

Should be written using this syntax:
var TTMRequired = (from g in tg.Groups
join e in tg.Enrolment on g.groupid equals e.groupid
join s in tg.Students on e.studentid equals s.studentid
join p in tg.Progressions on s.studentid = p.studentid
where p.academicyear.Equals("12/13") && g.istutorgroup.Equals(1)
group g by g.reference into grp
select new {
grpRef = grp.Key,
grpCount = grp.Count()
});
Note: if g.istutorgroup is of type BIT instead of INT, consider using .Equals(true).