private static void RemoveBattleFromSamuraiWhenDisconnected() { Samurai samurai; using (var seperateOperation = new BusinessDBContext()) { samurai = seperateOperation.Samurais.Include(s => s.SamuraiBattles) .ThenInclude(sb => sb.Battle) .SingleOrDefault(s => s.Id == 3); } var sbToRemove = samurai.SamuraiBattles.SingleOrDefault(sb => sb.BattleId == 1); samurai.SamuraiBattles.Remove(sbToRemove); //businessDbContext.Attach(samurai); //businessDbContext.ChangeTracker.DetectChanges(); businessDbContext.Remove(sbToRemove); businessDbContext.SaveChanges(); }