LINQ 查询返回在联接中没有关联记录的记录列表

发布于 2024-08-10 02:14:57 字数 344 浏览 5 评论 0原文

返回结果集是没有关联记录的记录的查询的最有效方法是什么？我正在使用 LINQ 和 Visual Basic，并一直尝试构造一个左外连接，然后筛选关联表中 id 为空或为 null 的记录，但对此我很陌生，无法进行任何操作。

想要做类似的事情：

Dim query = From s In db.spaces _
    Group Join t In db.tickets On s.spaceid Equals t.spaceid Into rs = Group _
    Select rs
End Function

我想返回整个左表减去这个结果集，但我是一个真正的菜鸟并且被卡住了。

原文

What is the most efficient way to return a query where the result set is those records that do NOT have an associated record? I am using LINQ and Visual Basic and have been trying to construct a left outer join and then filter on those records whose id is nothing or null in the associated table but am so new to this that I can't get anything to work.

Want to do something like:

Dim query = From s In db.spaces _
    Group Join t In db.tickets On s.spaceid Equals t.spaceid Into rs = Group _
    Select rs
End Function

I want to return the entire left table minus this result set but am a real noob and am stuck.

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向日葵 2024-08-17 02:14:57

从我的头顶上下来，希望它是对的！

Dim query = From s In db.spaces _
Group Join t In db.tickets On s.spaceid Equals t.spaceid Into rs = Group _
from xyz in rs.DefaultIfEmpty _
Select xyz

Off the top of my head, hope its right!!

Dim query = From s In db.spaces _
Group Join t In db.tickets On s.spaceid Equals t.spaceid Into rs = Group _
from xyz in rs.DefaultIfEmpty _
Select xyz

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