I have a 1 to many relation between user 1 =====> * Enrollment
so something like
User
{
public string UserName;
public IList<Enrollment> Enrollments;
}
and Enrollment have a CreateOn property
so
Enrollment
{
public DateTime CreateOn;
}
I would like to pull a list of User and project it to a list UserReport
where
UserReport
{
public string UserName;
public int EnrollmentCount;
public DateTime? LastEnrollment;
}
to do it in Linq would look something like this
var query = from user in UserRepository
select new UserReport ()
{
UserName = user.UserName,
EnrollmentCount = user.Enrollments.Count,
LastEnrollment = user.Enrollments
.OrderByDescending(enrollment =>
enrollment.CreateOn).
FirstOrDefault()
};
in fact that's how I currently do it. Pull the list of user and do this in
memory using Linq, but that mean I have to pull all the enrollments of every
users, extremely inefficient.
How do I do this with HQL, Criteria or QueryOver? I think I have to do some
projection... but how is beyond me.
So far I got this far
With HQL
select new UserReport(u.UserName) from User u; <--- though where do I add a
subquery that would give me the last enrollment
from u.Enrollments?
With Criteria I think I should create two criteria... one to select the last
enrollment and then join it with the main query but how is still beyond me.
--
You received this message because you are subscribed to the Google Groups
"nhusers" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/nhusers?hl=en.
