Question

I have 2 simple entities

1. Activity
2. ActivityViews

Activity Views has 2 properties ActivityID and DateTime. This entity allows me to see everytime an Activity was accessed.

I now want to write a LinqToEntity query that returns a list of Activities in descending order of how many times they have been viewed.

So far I have come up with this

  var activities= ((from a in db.Activities
                    join av in db.ActivityViews on a.ID equals av.Activity.ID
                    group a by new { a } into g
                    select new { g, No = g.Count() }).OrderByDescending(x => x.No)).Select(x => x.g).ToList();

It kind of works but its returning a list of annonymous types and I want to get a back a list of activity types. I dont want to return the count of views just for it to be ordered by them.

Edit : I take that back what I have doesnt work at all, if there are now ActivityViews for an Activity nothing gets returned.

Answer 1

Basically when you group whatever you group by is the key, so if you just select the key you will get what you need.

Here would be a solution to it.

var activities= 
  (
    (
       from a in db.Activities
       join av in db.ActivityViews
         on a.ID equals av.Activity.ID
       group a by a  into g
       select new { 
          a = g.Key, 
          No = g.Count() }
       ).OrderByDescending(x => x.No)
  ).Select(x => x.a)
  .ToList();

Working on simplifying this now.