Npgsql.PostgresException：42P01：关系“table”不存在

Question

当我尝试将数据放入“AccomodationCategories”表中时，我遇到了一个问题，但是我遇到了错误：

Npgsql.PostgresException：42P01：关系“AccomodationCategories”不存在

所以这就是我的表格：

当我保存我的“住宿”时，我在下拉列表中从“类别”表中选择一个类别。但是当我点击更新时它会出错。

这是我在AccomodationController中的代码：

[HttpPost]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> Edit(AccomodationDetailViewModel model, Int16 id)
        {
            var alert = new Alert();


            try 
            {
                if(!ModelState.IsValid)
                {
                    alert.Message = alert.ExceptionMessage = ApplicationDbContextMessage.INVALID;
                    throw new Exception();
                }    

                var originalModel = ApplicationDbContext.AccomodationDetails.FirstOrDefault(m => m.Id == model.AccomodationDetail.Id);

                //AccomodationCategories
                var modelC = await ApplicationDbContext.AccomodationCategories.FirstOrDefaultAsync(m => m.AccomodationId == id);
                var modelC2 = await ApplicationDbContext.AccomodationCategories.FirstOrDefaultAsync(m => m.CategoryId == id);

                var accoCat1 = ApplicationDbContext.AccomodationCategories.FirstOrDefault(m => m.AccomodationId == modelC.Accomodations.Id);
                var accoCat2 = ApplicationDbContext.AccomodationCategories.FirstOrDefault(m => m.CategoryId == modelC2.Categories.Id);  
                //

                if(originalModel == null) 
                {
                    alert.Message = alert.ExceptionMessage = ApplicationDbContextMessage.NOTEXISTS;
                    throw new Exception();
                }

                originalModel.Title = model.AccomodationDetail.Title;
                originalModel.Description = model.AccomodationDetail.Description;
                originalModel.RentalTypeId = model.AccomodationDetail.RentalTypeId;

                //AccomodationCategories
                accoCat1.AccomodationId = modelC.AccomodationId;
                accoCat2.CategoryId = modelC2.CategoryId;

                ApplicationDbContext.AccomodationCategories.Attach(accoCat1);
                ApplicationDbContext.AccomodationCategories.Attach(accoCat2);
                //

                ApplicationDbContext.AccomodationDetails.Attach(originalModel);
                ApplicationDbContext.Entry(originalModel).State = EntityState.Modified;

                if (await ApplicationDbContext.SaveChangesAsync() == 0)
                {
                    alert.Message = alert.ExceptionMessage = ApplicationDbContextMessage.EDITNOK;
                    throw new Exception();
                } 

                alert.Message = ApplicationDbContextMessage.EDITOK;
                return RedirectToAction("Index");
            }
            catch(Exception ex)
            {
                alert.Type = AlertType.Error;
                alert.ExceptionMessage = ex.Message;

                model = await ViewModel(model.AccomodationDetail);

                ModelState.AddModelError(string.Empty, alert.ExceptionMessage);
            }
            return View(model);
        }

这是我的ApplicationDbContext.cs中的代码

public DbSet<AccomodationCategory> AccomodationCategories { get; set; }

            // Many-To-Many in EF7 (10-10-2016)
            // Accomodation can have many categories
            // category can be assigned to many Accomodations
            builder.Entity<AccomodationCategory>()
                .HasKey(c => new { c.AccomodationId, c.CategoryId });

            builder.Entity<AccomodationCategory>()
                .HasOne(ac => ac.Accomodations)
                .WithMany(p => p.Categories)
                .HasForeignKey(ac => ac.AccomodationId);

            builder.Entity<AccomodationCategory>()
                .HasOne(ac => ac.Categories)
                .WithMany(a => a.Accomodations)
                .HasForeignKey(ac => ac.CategoryId);