Question

我试图弄清楚如何从DBSet获得模型，其中模型具有具有特定属性的关系模型。

示例：

List<Person> persons = context.Person.Where(p => p.Properties.Where(p => p.CountryCode == 1)).ToList();

一个人可以拥有多个财产，我只想获取在特定国家/地区拥有财产的人的列表。

Answer 1

您显然正在尝试加入。我想你要（伪代码）

var persons = (from p in Context.Person
              join pr in Context.Property on p.ID equals pr.PersonID
              where pr.CountryCode == 1
               select p).ToList();

Answer 2

您实际上可以尝试类似的事情，

_unitOfWork.GetRepository<AdvertTrade>()
                .GetQueryable()
                .AsNoTracking()
                // Make sure the advert trade does not have any related to this user
                .Include(at => at.UserRatings)
                .Where(at => at.Id.Equals(userRating.AdvertTradeId))
                .Any(at => at.UserRatings.Any(ur => ur.CreatedBy.Value.Equals(userId) && ur.DeletedOnUtc == null))

我没有使用.Where（）来发送垃圾邮件，而是利用Any（）查找嵌套的需求。

为了使事情更清楚，这是示例代码块，旧代码已被注释掉，您需要关注（我没有重构它，因为它很糟糕，但是因为我的ERD已更改）。

var payload = _unitOfWork.GetRepository<CurrencySource>()
                .GetQueryable()
                .AsNoTracking()
                // Make sure all currency sources are not disabled or deleted
                .Where(cs => cs.IsEnabled && cs.DeletedOnUtc == null)
                //.Include(x=>x.CurrencyPairComponents)
                //.ThenInclude(x=>x.CurrencyPair)
                //.ThenInclude(x=>x.PartialCurrencyPairs)
                //.Include(cs => cs.CurrencyPairs)
                //.ThenInclude(cp => cp.PartialCurrencyPairs)
                //.ThenInclude(pcp => pcp.Currency)
                //.Where(cs => cs.CurrencyPairComponents.Select(x=>x.CurrencyPair)
                //    // Make sure all currencypairs are not disabled or deleted
                //    .Any(cp => cp.IsEnabled && cp.DeletedOnUtc == null
                //               &&
                //               // Make sure none of the currency pair's partial currency pair is not disabled or deleted
                //               cp.PartialCurrencyPairs
                //                   .Any(pcp => pcp.Currency.IsEnabled && pcp.Currency.DeletedOnUtc == null)))
                .Select(cs => new
                {
                    id = cs.Id,
                    abbreviation = cs.Abbreviation,
                    name = cs.Name
                    //currencyPairs = cs.CurrencyPairComponents
                    //    .Select(cp => new
                    //    {
                    //        id = cp.Id,
                    //        partialCurrencyPairs = cp.CurrencyPair.PartialCurrencyPairs
                    //            .Select(pcp => new
                    //            {
                    //                currencyId = pcp.CurrencyId,
                    //                currency = new
                    //                {
                    //                    abbrv = pcp.Currency.Abbrv,
                    //                    currencyTypeId = pcp.Currency.CurrencyTypeId,
                    //                    currencyType = new
                    //                    {
                    //                        typeShortForm = pcp.Currency.CurrencyTypeId.GetDisplayName(),
                    //                        name = pcp.Currency.CurrencyTypeId.GetDisplayName()
                    //                    },
                    //                    name = pcp.Currency.Name,
                    //                    walletTypeId = pcp.Currency.WalletTypeId
                    //                },
                    //                isMain = pcp.IsMain
                    //            })
                    //    })
                });

请注意，我嵌套了一些LINQ声明。

.Where(cs => cs.CurrencyPairComponents.Select(x=>x.CurrencyPair)
                    // Make sure all currencypairs are not disabled or deleted
                    .Any(cp => cp.IsEnabled && cp.DeletedOnUtc == null
                               &&
                               // Make sure none of the currency pair's partial currency pair is not disabled or deleted
                               cp.PartialCurrencyPairs
                                   .Any(pcp => pcp.Currency.IsEnabled && pcp.Currency.DeletedOnUtc == null)))

具有关系的.NET Core EF Select对象

2 个答案: