查詢從SQL轉換爲LINQ

Question

我想下面的SQL查詢轉換爲LINQ

SELECT a.* 
FROM campaign_newslettersubscriber_track a 
     INNER JOIN (SELECT DISTINCT campaignid, 
            Min(id) AS id 
        FROM campaign_newslettersubscriber_track 
        GROUP BY campaignid) AS b 
       ON a.campaignid = b.campaignid 
        AND a.id = b.id 

Answer 1

var subquery = from c in objectContext.campaign_newslettersubscriber_track 
         group c by c.campaignid into g 
         select new 
         { 
          id = g.Min(x => x.campaignid), 
          campaignId = g.Key 
         }; 

var n = from c in objectContext.campaign_newslettersubscriber_track 
     join cin in subquery.Distinct() on c.campaignid equals cin.campaignId 
     select c; 

Answer 2

我會去了解一下所謂Linqer工具。

它可以採取T-SQL並將其轉換爲LINQ，LINQ to SQL（使用SqlMetal）或LINQ to Entities（使用EdmGen）。

請注意，這不是一個免費工具（在寫這篇文章的時候，一個許可證是$ 60.00，更多更便宜），並且不會轉換所有T-SQL功能，下面是支持的functions的列表。