流利的NHibernate：我如何將這個查詢作爲條件來編寫？

Question

數據結構如下： 房子有很多房間。每個房間都有很多人。

我想要做的就是讓所有人都住一間房子。在普通的SQL中，我會寫出以下內容：

SELECT * FROM Person WHERE Room_id 
IN 
(SELECT Id FROM Room WHERE House_id = 1) 

如何在Fluent NHibernate'ish代碼中編寫該代碼？

在這個例子中，我們可以假設實體和映射是這樣的：

家實體

public virtual int Id { get; set; } 
public virtual string Name { get; set; } 
public virtual IEnumerable<Room> Rooms { get; set; } 

家測繪

Id(x => x.Id); 
Map(x => x.Name); 
HasMany(x => x.Rooms); 

間實體

public virtual int Id { get; set; } 
public virtual string Name { get; set; } 
public virtual House House { get; set; } 
public virtual IEnumerable<Person> Persons { get; set; } 

間映射

Id(x => x.Id); 
Map(x => x.Name); 
References(x => x.House); 
HasMany(x => x.Persons); 

Person實體

public virtual int Id { get; set; } 
public virtual string Name { get; set; } 
public virtual Room Room { get; set; } 

Person的映射

Id(x => x.Id); 
Map(x => x.Name); 
References(x => x.Room); 

Answer 1

，收穫得SQL查詢到你的，你可以使用這些標準：

var subCriteria = DetachedCriteria.For<Room>(); // subquery 
subCriteria.Add(Expression.Eq("House", house)); // where clause in subquery 
subCriteria.SetProjection(Projections.Id()); // DetachedCriteria needs to have a projection, id of Room is projected here 

var criteria = session.CreateCriteria<Person>(); 
criteria.Add(Subqueries.PropertyIn("Room", subCriteria)); // in operator to search in detached criteria 
var result = criteria.List<Person>(); 

這將產生某物像這樣：

SELECT this_.Id as Id4_0_, this_.Name as Name4_0_, this_.RoomId as RoomId4_0_ 
FROM [Person] this_ 
WHERE this_.RoomId in (SELECT this_0_.Id as y0_ FROM [Room] this_0_ WHERE this_0_.HouseId = @p0)',N'@p0 int',@p0=1 

我測試了它在FNH1.2和NH3.1但應NH2.1中發揮作用。編輯： UpTheCreek是正確的。 Linq比Criteria API更清晰。例如：

var query = session.Query<Person>().Where(x => x.Room.House == house); 
var linqResult = query.ToList<Person>(); 

產生不同的SQL查詢，但結果集是一樣的：

select person0_.Id as Id4_, person0_.Name as Name4_, person0_.Room_id as Room3_4_ 
from [Person] person0_, [Room] room1_ 
where person0_.Room_id=room1_.Id and room1_.House_id=2