BL.Rol.getRolesUsuario C# (CSharp) Method

        public List<long> getRolesUsuario(string username)
        {
            try
            {
                List<long> rols = new List<long>();

                var userQuery = from u in entidad.usuarios
                                where u.username == username
                                select u;
                DataAccess.usuario usrtmp = userQuery.First();

                foreach (role rl in usrtmp.roles)
                {
                    rols.Add(rl.id);
                }

                return rols;
            }
            catch (Exception ex)
            {
                throw new Exception(ex.ToString() + " --Rol.cs / getRolesUsuario()");
            }
        }