Question

equal this

select id,name, count(*) from table group by id, name

what is in linq???

Answer 1

In case of entity framework it is better to return computed projection directly from SQL:

var query = from x in context.YourEntities
            group x by new { x.ID, x.Name } into y
            select new 
                {
                    y.Key.ID,
                    y.Key.Name,
                    y.Count()
                };

This will do Count in database and reduce amount of transferred data.