Felbook.Models.UserService.JoinGroup C# (CSharp) 메소드

        public void JoinGroup(User usr, Group grp)
        {
            usr.JoinedGroups.Add(grp);
            grp.Users.Add(usr);

            foreach (var parent in grp.Parents)
            {
                usr.JoinedGroups.Add(parent);
                parent.Users.Add(usr);
            }

            db.SaveChanges();
        }