LINQ将数据分组两次 [英] LINQ Grouping Data Twice

问题描述

对于这个可怕的标题抱歉，我不太确定如何解释我的问题。

我有一个对象，如下所示：

  CustAcct cust =新的CustAcct（）; 
 cust.Name =John Doe; 
 cust.Account =ABC123; 
 cust.OrderTotal = 123.43 
 cust.OrderQty = 4; 
 cust.TransDate =12/26/2010 13:00
  

t花太多时间批评下一部分，因为这实际上并没有处理购物车/客户的东西，但这个想法是一样的，我只是想用一些人人都很熟悉的东西。

一个账户可以有多个客户，而一个客户可以有多个账户。

所以你有：

 列表< CustAcct> custList = new List< CustAcct>（）; 
 custList.Add（John Doe，ABC123，123.43，4，12/26/2010 13:00）; 
 custList.Add（John Doe，ABC123，32.12，2，12/27/2010 10:00）; 
 custList.Add（John Doe，ABC321，43.34，1，12/28/2010 15:00）; 
 custList.Add（John Doe，ABC321，54.60，3，2010年12月28日16:00）; 
 custList.Add（Jane Zoe，ABC123，46.45，2，12/28/2010 17:00）; 
 custList.Add（Jane Zoe，ABC123，32.65，1，12/29/2010 12:00）; 
 custList.Add（Jane Zoe，ABC321，67.65，3，12/29/2010 23:00）; 
 custList.Add（Jane Zoe，ABC321，75.34，4，12/30/2010 08:00）; 
  

我想要做的是获得每个Account和Customer的所有OrderTotal和OrderQty的总和我的输出将如下所示：

 账户客户订单总数订单数量
 ABC123 John Doe 155.55 6 
 ABC321 John Doe 97.94 4 
 ABC123 Jane Zoe 79.10 3 
 ABC321 Jane Zoe 142.99 7 
  

I我已经通过我的LINQ to Objects书籍和101 LINQ Samples，并且无法弄清楚如何去做到这一点。谢谢。

解决方案

您可以像这样进行分组和总结：

 从custList中的ca获得
通过新的{ca.Name，ca.Account}转换成g 
选择新的{
 g.Key.Account，
 g.Key.Name，
 OrderTotal = g.Sum（o => o.OrderTotal），
 OrderQty = g.Sum（o => o.OrderQty）
}; 
  

看到它在行动 。

Apologies for the terrible title, I wasn't quite sure how to phrase my problem.

I have an object that looks like:

CustAcct cust = new CustAcct();
cust.Name = "John Doe";
cust.Account = "ABC123";
cust.OrderTotal = 123.43
cust.OrderQty = 4;
cust.TransDate = "12/26/2010 13:00"

Please don't spend too much time criticizing the next part because this really doesn't deal with a shopping cart/Customer stuff but the idea is the same, I just wanted to use something that everyone is pretty familiar with.

An account can have more than one customer, and a customer can have more than one account.

So you have:

List<CustAcct> custList = new List<CustAcct>();
custList.Add("John Doe", "ABC123", 123.43, 4, "12/26/2010 13:00");
custList.Add("John Doe", "ABC123", 32.12, 2, "12/27/2010 10:00");
custList.Add("John Doe", "ABC321", 43.34, 1, "12/28/2010 15:00");
custList.Add("John Doe", "ABC321", 54.60, 3, "12/28/2010 16:00");
custList.Add("Jane Zoe", "ABC123", 46.45, 2, "12/28/2010 17:00");
custList.Add("Jane Zoe", "ABC123", 32.65, 1, "12/29/2010 12:00");
custList.Add("Jane Zoe", "ABC321", 67.65, 3, "12/29/2010 23:00");
custList.Add("Jane Zoe", "ABC321", 75.34, 4, "12/30/2010 08:00");

What I would like to do is get the sum of all OrderTotal and OrderQty for each Account and Customer so my output will look like:

Account    Customer    OrderTotal    OrderQty
 ABC123     John Doe    155.55          6
 ABC321     John Doe     97.94          4
 ABC123     Jane Zoe     79.10          3
 ABC321     Jane Zoe    142.99          7

I've been through my LINQ to Objects book and 101 LINQ Samples and can't figure out how to go about getting this. Thanks.

解决方案

You can group and sum like this:

from ca in custList
group ca by new { ca.Name, ca.Account } into g
select new {
    g.Key.Account,
    g.Key.Name,
    OrderTotal = g.Sum(o => o.OrderTotal),
    OrderQty = g.Sum(o => o.OrderQty)
};

See it in action.

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