gruppo LINQ dalla sintassi delle espressioni

Question

Ho una query T-SQL simile a questo:

SELECT r_id, r_name, count(*) 
FROM RoomBindings 
GROUP BY r_id, r_name 

vorrei fare lo stesso utilizzando LINQ. Finora sono arrivato qui:

var rooms = from roomBinding in DALManager.Context.RoomBindings 
         group roomBinding by roomBinding.R_ID into g 
         select new { ID = g.Key }; 

Come posso estrarre il conteggio (*) e parte R_Name?

Answer 1

Prova questa:

var rooms = from roomBinding in DALManager.Context.RoomBindings 
         group roomBinding by new 
         { 
          Id = roomBinding.R_ID, 
          Name = roomBinding.r_name 
         } 
         into g 
         select new 
         { 
          Id = g.Key.Id, 
          Name = g.Key.Name, 
          Count = g.Count() 
         }; 

Edit da Nick - Aggiunta la sintassi catena di metodo per il confronto

var rooms = roomBinding.GroupBy(g => new { Id = g.R_ID, Name = g.r_name }) 
         .Select(g => new 
          { 
           Id = g.Key.Id, 
           Name = g.Key.Name, 
           Count = g.Count() 
          });