Linq2Sql通過多列聯接（通過OR運算符）？

Question

我可以翻譯一下：

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

變成linq2sql語句？ 基本上我想要這樣：

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

我知道，我可以通過Union構造來做到這一點，但是有比復制大多數查詢更好的方法嗎？

Answer 1

您不能在linq-to-sql中使用or on子句。 您需要做：

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 };

等效於sql的：

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