LINQ：使用INNER JOIN，组和SUM

我正在尝试使用LINQ执行以下SQL，并且我得到的距离最近的是做交叉连接和总计算。我知道必须有更好的方式来编写它，所以我正在向堆栈团队寻求帮助。LINQ：使用INNER JOIN，组和SUM

SELECT T1.Column1, T1.Column2, SUM(T3.Column1) AS Amount 
FROM T1 
    INNER JOIN T2 
     ON T1.T1ID = T2.T1ID 
    INNER JOIN T3 
     ON T2.T3ID = T3.T3ID 
GROUP BY T1.Column1, T1.Column2

我一直在努力为以下LINQ代码

var qTotal = from T2 in context.T2 
      from T3 in context.T3 
      where T3.T3ID == T3.T3ID 
      group T3 by T2.T1ID into gT2T3 
        from T1 in context.T1 
        where gT2T3.Key.Equals(T1.T1ID) 
        select new { T1.Column1,T1.Column2,Amount = gT2T3.Sum(t => t.Column1)};

我知道必须有把它写一个更好的办法，我只是不知道任何帮助将如何，是伟大的！

来源

2009-02-10 Nic

试试这个：

var total = from T1 in context.T1 
      join T2 in context.T2 on T1.T2ID equals T2.T2ID 
      join T3 in context.T3 on T2.T3ID equals T3.T3ID 
      group T3 by new { T1.Column1, T1.Column2 } into g 
      select new { 
       Column1 = T1.Column1, 
       Column2 = T2.Column2, 
       Amount = g.Sum(t3 => t3.Column1) 
      };

来源

2009-02-10 03:11:03

谢谢尼克，我最初的想法，答案是不正确的，但重读它，并再次执行它，我意识到我在最初尝试了一个错误，你的答案是现货。谢谢！ – Nic 2009-02-10 04:10:14

对我来说，（使用4.0），以下的作品。

var total = from T1 in context.T1 
      join T2 in context.T2 on T1.T2ID equals T2.T2ID 
      join T3 in context.T3 on T2.T3ID equals T3.T3ID 
      group T3 by new { T1.Column1, T1.Column2 } into g 
      select new { 
       Column1 = g.Key.Column1, 
       Column2 = g.Key.Column2, 
       Amount = g.Sum(t3 => t3.Column1) 
      };

来源

2012-04-25 17:12:15 twnaing

下面的代码为我工作：

      var credit = (from bm in BulkMessage 
          join sms in SMS on bm.BulkMessageId equals sms.BulkMessageId 
          where bm.ProfileId == pid && bm.IsActive == true 
          group sms by sms.SMSCredit into g 

          select new { SMSCredits = g.Sum(s => s.SMSCredit) }).FirstOrDefault();

来源

2016-06-10 06:41:18

LINQ：使用INNER JOIN，组和SUM

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