LINQ查询用SUM和ORDER BY [英] Linq Query with SUM and ORDER BY

问题描述

我有（C＃）类调用与项目编号（int）和一个分数（INT）财产命中。我跳过的细节休息，保持短。现在，在我的代码，我有哪些我需要做下面的选择（进入一个新的列表）一个巨大的列表：我需要得到所有Hit.Score的每一个人Hit.ItemID，按照分值进行排序的总和。所以，如果我有原始列表以下项目

 项ID = 3，分数= 5 
项ID = 1，得分= 5 
项ID = 2，分数= 5 
项ID = 3，得分= 1 
项ID = 1，分数= 8 
项ID = 2，得分= 10 
  

结果列表中应包含以下内容：

 项目编号= 2，得分= 15 
项ID = 1，得分= 13 
项ID = 3，分数= 6 
  

有人能帮忙吗？

解决方案

  VAR q =（从命中^ h通过新的{} h.ItemID 
 H组为HH 
选择新{
 hh.Key.ItemID，
得分= hh.Sum（S = GT; s.Score）
}）OrderByDescending（I => i.Score）; 
  

I have a (C#) class called Hit with an ItemID (int) and a Score (int) property. I skip the rest of the details to keep it short. Now in my code, I have a huge List on which I need to do the following select (into a new List): I need to get the sum of all Hit.Score's for each individual Hit.ItemID, ordered by Score. So if I have the following items in the original list

ItemID=3, Score=5
ItemID=1, Score=5
ItemID=2, Score=5
ItemID=3, Score=1
ItemID=1, Score=8
ItemID=2, Score=10

the resulting List should contain the following:

ItemID=2, Score=15
ItemID=1, Score=13
ItemID=3, Score=6

Can somebody help?

解决方案

var q = (from h in hits
    group h by new { h.ItemID } into hh
    select new {
        hh.Key.ItemID,
        Score = hh.Sum(s => s.Score)
    }).OrderByDescending(i => i.Score);

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