如何轉換SQL查詢到LINQ哪個contans子查詢

Question

我的查詢，如下所示

`Select * from daps_user_activity where Userid In (Select Userid from daps_portaluser where EMR_ID = 24855) ` 

什麼是LINQ請幫我等效查詢...

Answer 1

試試這個，這是你最好使用join在這種情況下，而不是一個子查詢：

var results = (from a in daps_user_activity 
       join u in daps_portaluser on a.Userid equals u.Userid 
       where u.EMR_ID == 24855 
       select a).ToList() 

Answer 2

或者，你可以這樣做：

var results = (from a in daps_user_activity 
       from u in daps_portaluser 
       where u.EMR_ID == 24855 
       && a.Userid == u.Userid 
       select a).ToList() 

對我來說，它更清楚地顯示主查詢和子查詢。

幸得在Convert SQL Query (with Correlated Subquery) to LINQ in C#