实体框架 包括为“单个”和“位置”返回不同的值
本文关键字:返回 位置 框架 单个 实体 包括 | 更新日期: 2024-10-24 11:48:18
我的应用程序可用于向包含用户集的单个用户和团队的组合发送消息。结构是这样的,一个Message
实体有一个Recipients
实体,而该实体又具有User
实体列表和Team
实体列表。
我正在尝试使用 EF Code First 和 Linq-to-Entities 获取Message
实体的列表,并且我想包含Recipients
和Teams
以避免以后出现大量延迟加载请求。
奇怪的是,如果我使用 Include 子句,团队列表总是空的。经过一番实验,它归结为:
var messages = GetAll()
.Include(m => m.Recipients.Teams)
.Where(m => m.Id == 123)
.ToList();
返回一个包含一条消息的列表,其中Teams
列表为空。(GetAll()
只返回一个IQueryable<Message>
。但如果我这样做
var message = GetAll()
.Include(m => m.Recipients.Teams)
.Single(m => m.Id == 123);
然后我得到一条消息,Teams
正确填充。
知道为什么会这样吗?
编辑:这是生成的 SQL(取自实体框架探查器(
where 语句
SELECT *
FROM (SELECT [Extent1].[Id] AS [Id],
[Extent1].[ParentRelation] AS [ParentRelation],
[Extent1].[CreatedUtc] AS [CreatedUtc],
[Extent1].[Subject] AS [Subject],
[Extent1].[Introduction] AS [Introduction],
[Extent1].[Body] AS [Body],
[Extent1].[GlobalId] AS [GlobalId],
[Extent1].[Team_Id] AS [Team_Id],
[Extent1].[Creator_Id] AS [Creator_Id],
[Extent1].[Parent_Id] AS [Parent_Id],
[Extent1].[ReplyTo_Id] AS [ReplyTo_Id],
[Join1].[Id1] AS [Id1],
[Join1].[ToSupervisors] AS [ToSupervisors],
[Join1].[Organisation_Id] AS [Organisation_Id],
[Join1].[Id2] AS [Id2],
[Join4].[Id3] AS [Id3],
[Join4].[Name] AS [Name],
[Join4].[CreatedUtc] AS [CreatedUtc1],
[Join4].[Description] AS [Description],
[Join4].[Color] AS [Color],
[Join4].[Status] AS [Status],
[Join4].[Organisation_Id] AS [Organisation_Id1],
CASE
WHEN ([Join4].[Recipients_Id1] IS NULL) THEN CAST(NULL AS int)
ELSE 1
END AS [C1]
FROM [dbo].[Messages] AS [Extent1]
INNER JOIN (SELECT [Extent2].[Id] AS [Id1],
[Extent2].[ToSupervisors] AS [ToSupervisors],
[Extent2].[Organisation_Id] AS [Organisation_Id],
[Extent3].[Id] AS [Id2]
FROM [dbo].[Recipients] AS [Extent2]
LEFT OUTER JOIN [dbo].[MessageExtensions] AS [Extent3]
ON [Extent2].[Id] = [Extent3].[Recipients_Id]) AS [Join1]
ON [Extent1].[Recipients_Id] = [Join1].[Id1]
LEFT OUTER JOIN (SELECT [Extent4].[Recipients_Id] AS [Recipients_Id1],
[Extent5].[Id] AS [Id3],
[Extent5].[Name] AS [Name],
[Extent5].[CreatedUtc] AS [CreatedUtc],
[Extent5].[Description] AS [Description],
[Extent5].[Color] AS [Color],
[Extent5].[Status] AS [Status],
[Extent5].[Organisation_Id] AS [Organisation_Id],
[Extent6].[Recipients_Id] AS [Recipients_Id2]
FROM [dbo].[RecipientsTeams] AS [Extent4]
INNER JOIN [dbo].[Teams] AS [Extent5]
ON [Extent4].[Team_Id] = [Extent5].[Id]
INNER JOIN [dbo].[MessageExtensions] AS [Extent6]
ON 1 = 1) AS [Join4]
ON ([Extent1].[Recipients_Id] = [Join4].[Recipients_Id2])
AND ([Extent1].[Recipients_Id] = [Join4].[Recipients_Id1])
WHERE 11021 = [Extent1].[Id]) AS [Project1]
ORDER BY [Project1].[Id] ASC,
[Project1].[Id1] ASC,
[Project1].[Id2] ASC,
[Project1].[C1] ASC
单个语句
SELECT *
FROM (SELECT [Limit1].[Id1] AS [Id],
[Limit1].[ParentRelation] AS [ParentRelation],
[Limit1].[CreatedUtc] AS [CreatedUtc],
[Limit1].[Subject] AS [Subject],
[Limit1].[Introduction] AS [Introduction],
[Limit1].[Body1] AS [Body],
[Limit1].[GlobalId1] AS [GlobalId],
[Limit1].[Team_Id] AS [Team_Id],
[Limit1].[Creator_Id] AS [Creator_Id],
[Limit1].[Parent_Id] AS [Parent_Id],
[Limit1].[ReplyTo_Id] AS [ReplyTo_Id],
[Limit1].[Id2] AS [Id1],
[Limit1].[ToSupervisors] AS [ToSupervisors],
[Limit1].[Organisation_Id] AS [Organisation_Id],
[Limit1].[Id3] AS [Id2],
[Join5].[Id4] AS [Id3],
[Join5].[Name] AS [Name],
[Join5].[CreatedUtc1] AS [CreatedUtc1],
[Join5].[Description] AS [Description],
[Join5].[Color] AS [Color],
[Join5].[Status] AS [Status],
[Join5].[Organisation_Id] AS [Organisation_Id1],
CASE
WHEN ([Join5].[Recipients_Id1] IS NULL) THEN CAST(NULL AS int)
ELSE 1
END AS [C1]
FROM (SELECT TOP (2) [Extent1].[Id] AS [Id1],
[Extent1].[ParentRelation] AS [ParentRelation],
[Extent1].[CreatedUtc] AS [CreatedUtc],
[Extent1].[Subject] AS [Subject],
[Extent1].[Introduction] AS [Introduction],
[Extent1].[Body] AS [Body1],
[Extent1].[GlobalId] AS [GlobalId1],
[Extent1].[Team_Id] AS [Team_Id],
[Extent1].[Creator_Id] AS [Creator_Id],
[Extent1].[Parent_Id] AS [Parent_Id],
[Extent1].[ReplyTo_Id] AS [ReplyTo_Id],
[Join1].[Id2],
[Join1].[ToSupervisors],
[Join1].[Organisation_Id],
[Join1].[Id3]
FROM [dbo].[Messages] AS [Extent1]
INNER JOIN (SELECT [Extent2].[Id] AS [Id2],
[Extent2].[ToSupervisors] AS [ToSupervisors],
[Extent2].[Organisation_Id] AS [Organisation_Id],
[Extent3].[Id] AS [Id3]
FROM [dbo].[Recipients] AS [Extent2]
LEFT OUTER JOIN [dbo].[MessageExtensions] AS [Extent3]
ON [Extent2].[Id] = [Extent3].[Recipients_Id]) AS [Join1]
ON [Extent1].[Recipients_Id] = [Join1].[Id2]
WHERE 11021 = [Extent1].[Id]) AS [Limit1]
LEFT OUTER JOIN (SELECT [Extent4].[Recipients_Id] AS [Recipients_Id1],
[Extent5].[Id] AS [Id4],
[Extent5].[Name] AS [Name],
[Extent5].[CreatedUtc] AS [CreatedUtc1],
[Extent5].[Description] AS [Description],
[Extent5].[Color] AS [Color],
[Extent5].[Status] AS [Status],
[Extent5].[Organisation_Id] AS [Organisation_Id],
[Join4].[Id5],
[Join4].[Recipients_Id2]
FROM [dbo].[RecipientsTeams] AS [Extent4]
INNER JOIN [dbo].[Teams] AS [Extent5]
ON [Extent4].[Team_Id] = [Extent5].[Id]
INNER JOIN (SELECT [Extent6].[Id] AS [Id5],
[Extent6].[Recipients_Id] AS [Recipients_Id2]
FROM [dbo].[Messages] AS [Extent6]
LEFT OUTER JOIN [dbo].[MessageExtensions] AS [Extent7]
ON [Extent6].[Recipients_Id] = [Extent7].[Recipients_Id]) AS [Join4]
ON [Extent4].[Recipients_Id] = [Join4].[Recipients_Id2]) AS [Join5]
ON [Limit1].[Id1] = [Join5].[Id5]) AS [Project1]
ORDER BY [Project1].[Id] ASC,
[Project1].[Id1] ASC,
[Project1].[Id2] ASC,
[Project1].[C1] ASC
当我手动运行这些查询时,我得到的结果相同。对于Where
,Team
相关的属性都是 NULL,而对于Single
,它们被填充。
编辑 2 GetAll
方法是存储库方法
public virtual IQueryable<T> GetAll()
{
return Context.Set<T>();
}
T
在哪里Message
你能试试这个吗?var messages = GetAll((。包括(m => m.收件人.团队( .其中(m => m.Id == 123(。选择(m=>m(;