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我正在使用Nhibernate 3.2打印SqlServer數據庫的c＃，並試圖使用multiquery和Futures來加載子集合。ToFuture的延遲加載子集合
反正我可以得到它使用LINQ to NHibernate的工作，但查看SQL時發送給它看起來好像它加載除了孩子所有的父對象爲子集取的對象（數據庫喜歡它是渴望加載）。我很好奇，如果有可能改變這種行爲，只拉動所需的子對象列。
下面是演示此問題的代碼示例。
public class Parent : Entity
{
public virtual string Name { get; set; }
public virtual IList<Child> Children { get; set; }
}
public class Child : Entity
{
public virtual int Age { get; set; }
public virtual string Name { get; set; }
public virtual Parent Parent { get; set; }
}
public class ChildClassMap : ClassMap<Child>
{
public ChildClassMap()
{
Id(x => x.Id,"Id");
Map(x => x.Age);
Map(x => x.Name);
this.References(x => x.Parent).Column("ParentId").ForeignKey("Id");
}
}
public class ParentClassMap : ClassMap<Parent>
{
public ParentClassMap()
{
Id(x => x.Id, "Id");
Map(x => x.Name);
this.HasMany(x => x.Children).KeyColumn("ParentId");
}
}
public class FamilyRepository : NHibernateRepository<Parent>
{
public Parent GetParent(int id)
{
using (var session = this.Session.OpenSession())
{
var parent = session.Query<Parent>()
.Where(p => p.Id == id);
parent.FetchMany(x => x.Children)
.ToFuture();
return parent.ToFuture().SingleOrDefault();
}
}
}
測試用例
[TestClass]
public class FamilyTests
{
[TestMethod]
public void Should_Get_Parent_And_Children()
{
// arrange
var repo = new FamilyRepository();
// act
var parent = repo.GetParent(1);
// assert
Assert.AreNotEqual(null, parent);
Assert.AreEqual("TheOldOne", parent.Name);
Assert.AreEqual(3, parent.Children.Count);
Assert.AreEqual(4, parent.Children[1].Age);
Assert.AreEqual("TheMiddleOne", parent.Children[1].Name);
}
}
SQL：
CREATE TABLE [dbo].[Parent](
[Id] [int] IDENTITY(1,1) NOT NULL,
[Name] [varchar](50) NOT NULL,
CONSTRAINT [PK_Parent] PRIMARY KEY CLUSTERED
(
[Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
CREATE TABLE [dbo].[Child](
[Id] [int] IDENTITY(1,1) NOT NULL,
[ParentId] [int] NOT NULL,
[Age] [int] NOT NULL,
[Name] [varchar](50) NOT NULL,
CONSTRAINT [PK_Child] PRIMARY KEY CLUSTERED
(
[Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
SET ANSI_PADDING OFF
GO
ALTER TABLE [dbo].[Child] WITH CHECK ADD CONSTRAINT [FK_Child_Parent] FOREIGN KEY([ParentId])
REFERENCES [dbo].[Parent] ([Id])
GO
ALTER TABLE [dbo].[Child] CHECK CONSTRAINT [FK_Child_Parent]
GO
Set Identity_Insert [dbo].[Parent] on
insert into [dbo].[Parent]
(Id, Name)
values (1, 'TheOldOne');
insert into [dbo].[Parent]
(Id, Name)
values (2, 'TheOtherOne');
Set Identity_Insert [dbo].[Parent] off
GO
Set Identity_Insert [dbo].[Child] on
insert into [dbo].[Child]
(Id, ParentId, Age, Name)
values(1,1,3,'TheYoungOne')
insert into [dbo].[Child]
(Id, ParentId, Age, Name)
values(2,1,4,'TheMiddleOne')
insert into [dbo].[Child]
(Id, ParentId, Age, Name)
values(3,1,7,'TheFirstOne')
Set Identity_Insert [dbo].[Child] off
從SQL事件探查器的輸出是：
exec sp_executesql N'
select parent0_.Id as Id3_0_, children1_.Id as Id2_1_, parent0_.Name as Name3_0_, children1_.Age as Age2_1_, children1_.Name as Name2_1_, children1_.ParentId as ParentId2_1_, children1_.ParentId as ParentId0__, children1_.Id as Id0__
from [Parent] parent0_ left outer join [Child] children1_ on parent0_.Id=children1_.ParentId where [email protected];
select parent0_.Id as Id3_, parent0_.Name as Name3_ from [Parent] parent0_ where [email protected];
',N'@p0 bigint,@p1 bigint',@p0=1,@p1=1
有沒有人有什麼建議？
感謝您的時間