相关疑难解决方法(0)

看起来实体框架(来自NuGet的最新版本)在为导航属性构建连接时可能忽略HasRequired配置,而不是定义的第一个.

例如,给定具有以下配置的POCO对象(Person):

var person = modelBuilder.Entity<Person>();
person.ToTable("The_Peoples");
person.HasKey(i => i.Id);
person.Property(i => i.Id).HasColumnName("the_people_id");
person.HasRequired(i => i.Address)
    .WithMany()
    .Map(map => map.MapKey("address_id"));
person.HasRequired(i => i.WorkPlace)
    .WithMany()
    .Map(map => map.MapKey("work_place_id"));

我正在尝试使用以下查询加载人员列表:

myContext.Set<People>()
    .Include(o => o.Address)
    .Include(o => o.WorkPlace);

实体框架生成以下查询:

FROM  [dbo].[The_Peoples] AS [Extent1]
INNER JOIN [dbo].[The_Addresses] AS [Extent2] ON [Extent1].[address_id] = [Extent2].[address_id]
LEFT OUTER JOIN [dbo].[The_Work_Places] AS [Extent3] ON [Extent1].[work_place_id] = [Extent3].[work_place_id]

请注意,*The_Addresses*表的连接是内连接(如预期的那样),但是,*The_Work_Places*的后续连接是外连接.鉴于Address和WorkPlace属性都标记为必需,我希望两个连接都是内连接.我还尝试使用Required属性标记Address和WorkPlace属性,但这没有任何效果.

这是一个错误还是我可能错误配置了什么？建议？

(来自Julia Lerman的新实体框架书中的一个例子.)我有一个包含两个表的数据库,联系人和地址.Contact表有一个ContactID(int),以及名字,姓氏等.地址表有一个ContactID,以及city,state,zip等.

这是一个简单的LINQ查询:

var addressGraphQuery = from a in context.Addresses.Include("Contact")
                        orderby a.Contact.LastName, a.Contact.FirstName
                        select a;

从SQL事件探查器,我看到以下内容:

SELECT 
    [Extent1].[addressID] AS [addressID], 
    [Extent1].[City] AS [City], 
    [Extent1].[StateProvince] AS [StateProvince], 
    -- etc
    [Extent3].[ContactID] AS [ContactID1], 
    [Extent3].[FirstName] AS [FirstName], 
    [Extent3].[LastName] AS [LastName], 
    -- etc
FROM   [dbo].[Address] AS [Extent1]
INNER JOIN [dbo].[Contact] AS [Extent2] ON [Extent1].[ContactID] = [Extent2].[ContactID]
LEFT OUTER JOIN [dbo].[Contact] AS [Extent3] ON [Extent1].[ContactID] = [Extent3].[ContactID]
ORDER BY [Extent2].[LastName] ASC, [Extent3].[FirstName] ASC

它连接两次联系表!为什么？有没有一种简单的方法来防止这种情况？

神秘感加深了.当我删除orderby时,连接消失.当我设置时,连接不会消失context.ContextOptions.LazyLoadingEnabled = false.

这里也有一个类似的问题:

实体框架4中有太多左外连接？

我会看看是否有更高的功率我可以问...