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Linq to Entities:左连接以获取连接中未找到的项目

entity-framework asp.net

0

bugfixr · 技术社区 · 16 年前

TimeData table 
- userID 
- taskID 
- hours

ApprovedTasks table (the one that should contain nulls)
- taskID 
- userID

SQL查询看起来像这样:

select * from TimeData td 
left join ApprovedTasks at
 on at.taskID = td.taskID and at.userID = td.userID
where at.taskID is null

有什么方法可以使用LINQ to Entity查询来实现这一点吗?

短暂性脑缺血发作

1 回复 | 直到 16 年前

1

3

Community Mohan Dere 8 年前

Disjoint Union in LINQ

var approvedTaks = from at in ApprovedTasks.Except(
                                        from at2 in ApprovedTasks
                                        where at2.userID == userId and at2.taskID==taskId
                                        select at2)
                    where at.userID == userId and at.taskID==taskId
                    select at;