如何使用LINQ连接多个表

我正试图用LINQ连接三个表。 我的SQL工作如下：

Select j.Id, u.FirstName , u.LastName, u.Role From Job j left join JobTranslator as jt on j.Id = jt.JobId left join JobRevisor as jr on j.Id = jr.JobId left join [User] as u on jt.UserId = u.Id OR jr.UserId = u.Id Where u.Id = someID; 

我可以使用下面的两个连接来使用它：

  IQueryable jobs = from j in _db.Jobs join jr in _db.JobRevisors on j.Id equals jr.JobId into jrs from jrResult in jrs.DefaultIfEmpty() join u in _db.Users on jrResult.UserId equals u.Id into jrU from jrUResult in jrU.DefaultIfEmpty() where jrUResult.Id == userId orderby j.Id select j; 

但是当我尝试加入我最后需要的表时，它不像下面那样工作。

 IQueryable jobs = from j in _db.Jobs join jt in _db.JobTranslators on j.Id equals jt.JobId into jts from jtResult in jts.DefaultIfEmpty() join jr in _db.JobRevisors on jtResult.Id equals jr.JobId into jrs from jrResult in jrs.DefaultIfEmpty() join u in _db.Users on jrResult.UserId equals u.Id into jrU from jrUResult in jrU.DefaultIfEmpty() join u in _db.Users on jtResult.UserId equals u.Id into jtU from jtUResult in jtU.DefaultIfEmpty() where jtUResult.Id == userId orderby j.Id select j; 

任何人的想法？

Answer 1

来自Linq – 在多个（OR）条件下左连接 ：

 IQueryable jobs = (from j in _db.Jobs join jt in _db.JobTranslators on j.Id equals jt.JobId into jts from jtResult in jts.DefaultIfEmpty() join jr in _db.JobRevisors on jtResult.Id equals jr.JobId into jrs from jrResult in jrs.DefaultIfEmpty() join u in _db.Users on jtResult.UserId equals u.Id into jtU from jtUResult in jtU.DefaultIfEmpty() where jtUResult.Id == userId orderby j.Id select j).Concat( from j in _db.Jobs join jt in _db.JobTranslators on j.Id equals jt.JobId into jts from jtResult in jts.DefaultIfEmpty() join jr in _db.JobRevisors on jtResult.Id equals jr.JobId into jrs from jrResult in jrs.DefaultIfEmpty() join u in _db.Users on jrResult.UserId equals u.Id into jrU from jrUResult in jrU.DefaultIfEmpty() where jtUResult.Id == userId orderby j.Id select j ).Distinct()