Linq2Sql通过多列连接(通过OR运算符)?

时间:2016-10-17 07:14:43

标签: c# linq linq-to-sql

我可以翻译一下:

SELECT * 
FROM vectors as v
INNER JOIN points as p 
ON v.beginId = p.id OR v.endId = p.id

进入linq2sql语句?基本上我想要这个:

var query = from v in dc.vectors
            join p in dc.points on p.id in (v.beginId, v.endId)
            ...
            select ...;

我知道,我可以通过Union构建来做到这一点,但有没有比复制大部分查询更好的方法?

1 个答案:

答案 0 :(得分:2)

在linq-to-sql中,on不能有or子句。你需要这样做:

var result = from v in dc.vectors
             from p in dc.points
             where p.id == v.beginId || p.id == v.endId
             select new { v, p };

相当于sql:

SELECT * 
FROM vectors as v,
     points as p 
WHERE v.beginId = p.id 
OR v.endId = p.id