LinQ& DataTable Group by C＃ [英] LinQ & DataTable Group By Question in C#

问题描述

我有一个DataTable并存储4列（StockCardCode，Explain，Quantity，BranchCode）和Im将其与LinQ进行分组。代码是我使用Group By的关键。当我写我的查询时，我可以在select语句中使用2列，我该如何显示此查询中的所有列？此查询返回2列。我不能在我的查询中使用x.Field（Explain）。

  var query = from in in incoming.AsEnumerable （）
 group s by s.Field< string>（Stock card Code）
 into grp 
 orderby grp.Key 
 select new {StockCardCode = grp.Key，Quantity = grp.Sum（r => r.Field< decimal>（Quantity））}; 
  

传入：DataTable

解决方案

由于您是通过StockCardQuote进行分组，因此Explain值将是具有相同StockCardQuote的行的所有解释值 - 它将成为 IEnumerable< T> ，所以如果说是一个字符串，你会得到 IEnumerable< string> 。

要将其包含在您的选择语句中，只需执行

  select new {
 StockCardCode = grp.Key，
 Quantity = grp.Sum（r => r。字段< decimal>（Quantity）），
说明= grp.Select（r => r.Field< string>（Explain））}; 
  

I have a DataTable and stores 4 columns (StockCardCode,Explain,Quantity,BranchCode), and Im grouping them with a LinQ. Code is my key for using Group By. When I write my query, I just can use 2 columns in select statement, how can I show all columns in this query? This query returns me 2 column. I cant use x.Field("Explain") in my query for example.

var query = from s in incoming.AsEnumerable()
                        group s by s.Field<string>("Stock Card Code")
                            into grp
                            orderby grp.Key
                            select new { StockCardCode = grp.Key, Quantity = grp.Sum(r => r.Field<decimal>("Quantity")) };

incoming: DataTable

解决方案

Since you are grouping by StockCardQuote, the "Explain" value is going to be all of the Explain values from rows with the same StockCardQuote -- it is going to be an IEnumerable<T>, so if Explain is a string, you'll get IEnumerable<string>.

To include this in your select statement, just do

select new { 
    StockCardCode = grp.Key, 
    Quantity = grp.Sum(r => r.Field<decimal>("Quantity")),
    Explanations = grp.Select(r => r.Field<string>("Explain")) };

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