BL.Rol.getRolesID C# (CSharp) Метод

        public List<long> getRolesID()
        {
            try
            {
                var allRolsID = from r in entidad.roles
                              select r.id;

                return allRolsID.ToList();
            }
            catch (Exception ex)
            {
                throw new Exception(ex.ToString() + " --Rol.cs / getRolesID()");
            }
        }