NHibernate的投影組件

Question

好傢伙我試着去水合物DTO使用投影NHibernate的，這是我的代碼

IList<PatientListViewModel> list = 
            y.CreateCriteria<Patient>()         
              .SetProjection(Projections.ProjectionList() 
              .Add(Projections.Property("Birthdate"), "Birthdate") 
              .Add(Projections.Property("Doctor.Id"), "DoctorId") 
              .Add(Projections.Property("Gender"), "Gender") 
              .Add(Projections.Property("Id"), "PatientId") 
              .Add(Projections.Property("Patient.Name.Fullname"), "Fullname")  
           ) 
         .SetResultTransformer(Transformers.AliasToBean<PatientListViewModel>()) 
         .List<PatientListViewModel>(); 

此代碼拋出異常？任何人都知道什麼是問題？

這裏是錯誤消息

Message: could not resolve property: Patient.Name.Fullname of: OneCare.Domain.Entities.Patient 

Answer 1

你必須創建一個連接到您的Parent.Name財產。

所以嘗試設置投影別名創建您Patient.Name財產

e.q.前

IList<PatientListViewModel> list = 
           y.CreateCriteria<Patient>() 
           .CreateAlias("Name", "name") 

             .SetProjection(Projections.ProjectionList() 
             .Add(Projections.Property("Birthdate"), "Birthdate") 
             .Add(Projections.Property("Doctor.Id"), "DoctorId") 
             .Add(Projections.Property("Gender"), "Gender") 
             .Add(Projections.Property("Id"), "PatientId") 
             .Add(Projections.Property("name.Fullname"), "Fullname")  
          ) 

對不起，我沒有檢查這一點，因爲所有這些都取決於你的實體類。但是這個想法是你必須創建一個別名。 如果您無法解決問題，請提供您的課程。

更新！

我創建了兩個實體，病人和醫生：

public class Patient : AdvanceEntity 
{ 
    public virtual DateTime BirthDate { get; set; } 

    public virtual Doctor Doctor { get; set; } 

    public virtual int Gender { get; set; } 

    public virtual string Name { get; set; } 
} 

public class Doctor : AdvanceEntity 
{ 
    public virtual string Name { get; set; } 
} 

下一頁庫只包含你的查詢轉換爲標準API

public IList<Patient> GetPatientsForDoctor(long doctorId) 
    { 
     return this.Session.CreateCriteria(typeof(Patient), "patient") 
      .CreateAlias("patient.Doctor", "doc") 
      .Add(Restrictions.Eq("doc.Id", doctorId)) 
      .List<Patient>() 
     ; 
    } 

這裏是單元測試和的結果查詢

[Test] 
    public void CanGetPatients() 
    { 
     var repository = new PatientRepository(); 
     repository.GetPatientsForDoctor(1L); 
    } 

並且結果是：

NHibernate: SELECT this_.patientId as patientId70_1_, this_.birthDate as birthDate70_1_, this_.gender as gender70_1_, 
this_.name as name70_1_, this_.deletedDate as deletedD5_70_1_, this_.doctorId as doctorId70_1_, 
this_.deletedById as deletedB7_70_1_, doc1_.doctorId as doctorId71_0_, doc1_.name as name71_0_, 
doc1_.deletedDate as deletedD3_71_0_, doc1_.deletedById as deletedB4_71_0_ 
FROM Patients this_ 
inner join Doctors doc1_ on this_.doctorId=doc1_.doctorId 
WHERE doc1_.doctorId = @p0;@p0 = 1 

正如我所說的，你只需要創建一個別名並在它們之間連接表。 但我認爲，在這種情況下使用HQL更合理。使用標準只有你有動態查詢。正如你所看到的，選擇所有可能導致性能缺失的領域的標準。你正在處理簡單的事情，但在實際應用中要非常小心地生成查詢。

祝您有美好的一天！