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我在嘗試寫以下情況的查詢巨大的困難：NHibernate的子查詢
在我的核心框架（至極我不能修改，因爲這不是我們的代碼）我有兩個類：
[Class(Table = "Teacher")]
public class Teacher
{
[Id]
public virtual long? Id {get;set;}
[Property]
public virtual string EmployeeNr{get;set;}
}
[Class(Table = "Student")]
public class Student
{
[Id]
public virtual long? Id{get;set;}
[Property]
public virtual string Name{get;set;}
}
接下來，在我的應用程序層我已經建立了下面的類來記錄學生和教師做測試
[Class(Table = "TestReports", DiscriminatorValueObject = 1)]
public class TestReport
{
[Id]
public virtual long? Id{get;set;}
[Property]
public virtual string TestName{get;set;}
[Property]
public virtual DateTime Date{get;set;}
[Property]
public virtual int Correct{get;set;}
[Property]
public virtual int InCorrect{get;set;}
[Property]
public virtual int Unanswerd{get;set;}
}
[Subclass(NameType = typeof(StudentTestReport), ExtendsType = typeof(TestReport), DiscriminatorValueObject = 2)]
public class StudentTestReport
{
[ManyToOne]
public virtual Student Student{get;set;}
}
[Subclass(NameType = typeof(TeacherTestReport), ExtendsType = typeof(TestReport), DiscriminatorValueObject = 3)]
public class TeacherTestReport
{
[ManyToOne]
public virtual Teacher Teacher{get;set;}
}
現在的信息我想是一個查詢來獲取最後testreportØ f所有學生和老師但是如果老師或學生沒有進行任何測試，他們仍應該在概覽中顯示。所以我決定採取AliasToBeanTranformer方法和創建報表的包裝對象：
public class TestOverviewWrapper
{
public virtual string TestName{get;set;}
public virtual DateTime Date{get;set;}
public virtual int Correct{get;set;}
public virtual int InCorrect{get;set;}
public virtual int Unanswerd{get;set;}
public virtual long Id{get;set;}
public virtual string Name{get;set;}
public virtual string EmployeeNr{get;set;}
public virtual string Person
{
get{ return Name ?? EmployeeNr;}
}
}
我有巨大的麻煩越來越查詢權，我想看看我是否能得到的只是學生和他們的最後一次測試報告，但我卡住投影到包裝對象的子查詢的屬性。這是我在多大程度上得到：
public IList<TestOverviewWrapper> GetTestOverview()
{
var crit = SessionFactory.GetCurrentSession().CreateCriteria<Student>("st");
var dcrit = DetachedCriteria.For<StudentTestReport>("lastTest")
.Add(Subqueries.PropertyEq("Date",
DetachedCriteria.For<StudentTestReport>("test")
.Add(Restrictions.EqProperty("lastTest.Student", "st.Id"))
.SetProjection(Projections.Max("lastTest.Date"))));
dcrit.Add(Restrictions.EqProperty("lastTest.Student", "st.Id"));
crit.Add(Subqueries.Select(dcrit));
crit.SetProjection(Projections.ProjectionList()
.Add(Projections.Property("lastTest.Id")
.Add(Projections.Property("lastTest.TestName")
.Add(Projections.Property("lastTest.Date")
.Add(Projections.Property("lastTest.Correct")
.Add(Projections.Property("lastTest.Incorrect")
.Add(Projections.Property("lastTest.Unanswerd")
.Add(Projections.Property("st.Id")
.Add(Projections.Property("st.Name")
);
crit.SetResultTransformer(Transformers.AliasToBean<TestOverview>());
return crit.List<TestOverviewWrapper>();
}
任何人都可以點我在正確的方向，記得我不能對學生和教師類添加映射