Question

I have the following two table:

-Groups-
Id
Name

-Members-
Id
GroupId (Group.Id is related to Member.GroupId)
Name
IsActive (bit)

How can I writing a LINQ query that will sort by the number of IsActive members highest to lowest in a group?

The query would look something like this

//pseudo code
    from grp in database.Groups
    orderby Count(grp.Members.where(m=>m.IsActive == true)) descending
    select grp

Answer 1

You can use let clause for this.
As a result you will get following:

from grp in database.Groups
let activeCount = grp.Members.Where(m=>m.IsActive == true).Count()
order by activeCount descending
select grp

Another way to achive desired ordering is to use select ... into. Queries will be pretty similar, but you should be aware of differences between this two approaches: Is linq’s let keyword better than its into keyword?