c# - .Include() .Where() 在 Linq to Entities 查询中

Question

我试图找到所有活跃的患者，那些有 EndOfTreatment == null 的患者.

问题是这种关系具有复杂的结构。

我不太擅长这些数据库图表的东西，但我做了以下图片，我想你会明白这一点:



到目前为止我的尝试:

var ans = ctx
    .PatientMap
    .Include(p => p.Doctor)
    .Include(p => p.Product)
    .Include(p => p.Institution)
    .Include(p => p.Doctor.TerritoryDoctorPanel
        .Where(dp =>
            (dp.Territory.PromotionalLine == p.Product.PromotionalLine) &&  // issuing
            (dp.Territory.Active == true)                                   // lines
        )
    )
    .Where(p =>
        (IDProduct == null || p.IDProduct == IDProduct.Value) &&
        (p.EndOfTreatment == null)
    )
    .ToList()
    .Select(p => new ActivePatientModel
    {
        IDPatient = p.ID,
        Observation = p.Observation,
        TreatmentPeriod = DateTimeSpan.CompareDates(
            (DateTime)p.StartOfTreatment, DateTime.Now
        ).Months,
        NameDoctor = p.Doctor.FullName,
        CodeDoctor = p.Doctor.Code,
        CodeInstitution = p.Institution.Code,
    })
    .ToList();

我搜索了很多，我得到的最接近的是 this answer from Moho ，经过调整后看起来像:

.SelectMany(p => p.Doctor.TerritoryDoctorPanel)
    .Where(dp => dp.Territory.PromotionalLine == /*p.Product.PromotionalLine*/)
                                                   ^^^^^^^^^^
                                                // How can I reference p.Product here?

恢复:

我需要获取 Patients由 Doctors 处理使用一些 Product在 Territories 工作.关系存在于 Product.PromotionalLine = Territory.PromotionalLine .

IDProduct类型为 int? ，因此:(IDProduct == null || p.IDProduct == IDProduct.Value)

我真的不知道如何让它发挥作用。

我很感激任何建议。

Answer 1

我会尝试一些东西，我希望我能清楚地了解你的想法，尽管我不确定我是否做到了。

所以我想你的问题是这个

I need to get Patients treated by Doctors using some Product working in Territories. The relationship exists

这是我将如何做到的。

var ans = ctx
    .PatientMap
    .Include(p => p.Doctor)
    .Include(p => p.Product)
    .Include(p => p.Institution)
    .Include(p => p.Doctor.TerritoryDoctorPanel
    .Where(p => 
        // some doctors, doctorIDs is list of all doctors id you want in case you are using id retrieval 
       doctorIDs.Contains(p.DoctorID) &&
       //working in some territory 
       //similar to this, you can filter any doctor Attribute 
       p.Doctor.TerritoryDoctorPanel.Any(t => /*Add condition for TerritoryDoctorPanel here */) &&
      (p.IDProduct == null || p.IDProduct == IDProduct.Value) &&
      (p.EndOfTreatment == null) && 
       // Product Promotion line conditions
       // also similar to this you can filter any product attribute 
      (p.Product.PromotionalLine.Any(pl => /*Add condition for promotional lines here*/)))             
    .ToList()