在多对多关系中访问 EF Core 中最后一个 table 的属性

Question

我在商店的主页上显示产品时出错，其中可以使用品牌和其他项目等过滤器。

我服务的所有部分都正常工作。但是我要过滤产品组的部分有错误。简要PG

组table是另外两个table的接口table。我也试过这个从组table开始，但我看到的是每个产品重复几次。

public Tuple<List<ShowProductBoxListViewModel>, int>
        GetProductList(int pageId = 1, string filter = "", List<int> brandId = null,
            string getType = "all", List<int> tWidth = null, List<int> rDiameter = null,
            List<int> PG = null, string orderByType = "date", int startPrice = 0,
            int endPrice = 0, List<int> selectedGroups = null, int take = 0)
    {
        if (take == 0)
        {
            take = 8;
        }

        IQueryable<Product> result = _context.Products
            .Include(c => c.Groups)
            .ThenInclude(c => c.ProductGroup);

        if (!string.IsNullOrEmpty(filter))
        {
            result = result.Where(p => p.Title.Contains(filter) || p.Brand.Title.Contains(filter));
        }
        if (brandId.Count != 0)
        {
            result = result.Where(c => brandId.Contains(c.BrandId));
        }
        switch (getType)
        {
            case "all":
                var test = result.Count();
                break;
            case "discountPrice":
                var now = DateTime.Now;
                result = result.Where(c => c.PurchasePrice != null
                                           && c.StartDiscountTime.HasValue
                                           && c.StartDiscountTime < now
                                           && c.EndDiscountTime.HasValue
                                           && c.EndDiscountTime > now);
                break;
        }
        if (tWidth.Count != 0)
        {
            result = result.Where(c => tWidth.Contains(c.TireWidthId));
        }
        if (rDiameter.Count != 0)
        {
            result = result.Where(c => rDiameter.Contains(c.TireDiameterId));
        }
        if (PG.Count != 0)
        {
            //result = result.Where(c => PG.Contains(c.id.GroupId));
        }
        if (startPrice > 0)
        {
            result = result.Where(p => p.Price > startPrice);
        }
        if (endPrice > 0)
        {
            result = result.Where(p => p.Price < endPrice);
        }

        if (getType == "all")
        {
            switch (orderByType)
            {
                case "date":
                    {
                        result = result.OrderByDescending
                                (p => p.CreateDate);
                        break;
                    }
                case "lowPrice":
                    {
                        result = result.OrderBy(p => p.Price);
                        break;
                    }
                case "highPrice":
                    {
                        result = result.OrderByDescending(p => p.Price);
                        break;
                    }
            }

        }
        else if (getType == "discountPrice")
        {
            switch (orderByType)
            {
                case "date":
                    {
                        if (result != null)
                        {
                            result = result.OrderByDescending(p => p.CreateDate);
                            var test = result.Count();
                        }
                        break;
                    }
                case "lowPrice":
                    {
                        if (result != null)
                        {
                            result = result.OrderBy(p => p.PurchasePrice);
                        }

                        break;
                    }
                case "highPrice":
                    {
                        if (result != null)
                        {
                            result = result.OrderByDescending(p => p.PurchasePrice);
                        }
                        break;
                    }
            }
        }
        int skip = (pageId - 1) * take;
        int pageCount;
        if (result != null)
        {
            pageCount = result.Count() / take +1;
        }
        else
        {
            pageCount = 0;
        }

        List<ShowProductBoxListViewModel> query = null;
        if (result != null)
        {
            query = result.Select(p => new ShowProductBoxListViewModel()
            {
                ProductId = p.ProductId,
                ProductImage = p.ProductImageName,
                Priceoffer = p.PurchasePrice,
                Price = p.Price,
                ProductTitle = p.Title,
                ProductUrl = p.Url,
                BrandName = p.Brand.Name,
                BrandLogo = p.Brand.ImageName,
                ProductDeep = p.ProductDeep,
                WeightCode = p.WeightCode.Code,
                WeightTitle = p.WeightCode.Title,
                SpeedCode = p.SpeedCode.Code,
                SpeedTitle = p.SpeedCode.Title,
                RingDiameter = p.TireDiameter.Code,
                BrandId = p.BrandId,
                ProductWidth = p.TireWidth.Code,
                EndDiscountTme = p.EndDiscountTime,
                ProductCreateDate = p.ProductCreateDate,
                StockProduct = p.Stock
            }).Skip(skip).Take(take).ToList();

        }

        return Tuple.Create(query, pageCount);
    }

为了方便访问，我再说一遍： 我的错误在以下部分：

result = result.Where (c => PG.Contains (c.Group.GoupId));

我认为对于我所写的关系，我根本无权访问组属性。 图片已添加。 Image For Access the properties of the last table in ef core in many to many relationships 如果还需要模型。我会在下次更新时放上去。

Answer 1

PG也可以为null，Id不能包含GroupId

 if (PG!=null && PG.Count > 0)
        {
           result = result.Where(c =>   c.Groups.Any ( g=> PG.Contains(g.GroupId));
        }