如何在Entity Framework中使用’In’SQL关键字？

这是我的SQL命令

SELECT KEY,NAME from COMPANY c WHERE KEY IN (select KEY from USER_COMPANY where UserId = @UserId) order by NAME asc 

所以我想将其转换为Entity Framework。

我试试这个

  var userCompany = (from u in db.USER_COMPANY where u.UserId == UserId select(u.KEY)); var user = (from c in db.COMPANY where (c => userCompany.Contains(c.KEY) select c); 

但它不起作用。

如何在Entity Framework中使用SQL IN关键字？

Answer 1

试试这个：

 var query = from c in db.COMPANY where (from u in db.USER_COMPANY where u.UserId == UserId select u.KEY).Contains(c.KEY) orderby c.NAME select c.KEY, c.NAME; 

Answer 2

请注意，此SQL查询具有完全相同的含义：

 SELECT c.KEY, c.NAME FROM COMPANY c JOIN (SELECT DISTINCT KEY FROM USER_COMPANY where UserId = @UserId) u ON U.KEY = C.KEY ORDER BY c.NAME asc 

所以你应该能够做到：

 var userCompany = (from u in db.USER_COMPANY where u.UserId == UserId select(u.KEY)).Distinct(); var result = from c in db.COMPANY join u in userCompany on c.KEY = u.KEY select new {c.KEY, c.NAME}; 

Answer 3

我的理解是从.Contains()到IN的转换只是被添加到EF6。

根据此工作项（ http://entityframework.codeplex.com/workitem/245 ）和发行说明：改进了LINQ查询中Enumerable.Contains的性能。

所以在EF6中寻找它

Answer 4

您可以使用entity framework执行原始SQL查询。 看看这个链接： http ： //msdn.microsoft.com/en-us/data/jj592907.aspx