Question

Is it possible to have a where clause with a previous list ?

For exemple :

List<Stable> StableList= db.Stables.Where(s => s.OwnerId == user.UserId).ToList();

List<Pony> PonyList= db.Ponys.Where(p=> p.PonyStableId == {StableList.StableId })OrderByDescending(p => p.PostDate).ToList();

Answer 1

List<int> StableList= db.Stables.Where(s => s.OwnerId == user.UserId)
                             .Select(s => s.StableId)
                             .ToList();


List<Pony> PonyList= db.Ponys.Where(p=> StableList.Contains(p.PonyStableId))
                             .OrderByDescending(p => p.PostDate)
                             .ToList();

Probably not the most efficient. You could do a Join between Stables and Ponys where Stable.OwnderId == User.UserId. That would work too.