linq - LINQ 双连接语句

Question

我有一个名为 Workbook 的表，它与表“Revisorsberetning”具有一对多的关系，该表与 Project 是多对一的关系。所以：工作簿 --> Revisorsberetning --> 项目

我只想获取与给定 WorkbookId 的工作簿相关的项目列表

我尝试将以下 SQL（SQL 工作）转换为 LINQ，但没有成功：

select Project.PROJECT_NAME
from Project
inner join dbo.Revisorsberetning
on dbo.Revisorsberetning.Project_ProjectId = dbo.Project.ProjectId
inner join dbo.Workbook
on dbo.Workbook.WorkbookId = 2

这是似乎无法正常工作的 LINQ（LinqPAD，这就是为什么您看到 projectS 而没有 dbcontext）查询：

var sss = from u in Projects
join uc in Revisorsberetnings on u.ProjectId equals uc.Project.ProjectId
join c in Workbooks on uc.Workbook.WorkbookId  equals c.WorkbookId
where c.WorkbookId == 2
select u.PROJECT_NAME;

Answer 1

试试这个变种

var sss = from u in Projects
          join uc in Revisorsberetnings on u.ProjectId equals uc.Project.ProjectId
          from c in Workbooks
          where c.WorkbookId == 2
          select u.PROJECT_NAME;