LINQ按查询分组 [英] Linq group by query

问题描述

试图计算一个linq查询，想知道你们是否可以提供帮助.

Trying to work out a linq query and was wondering if you guys could help.

我有一个对象foo的列表，每个foo对象都有一个bar的列表.栏有一个有效的日期和一个数值.例如

I have a list of objects foo and each foo object has a list of bar. bar has an active date and a numeric value. for example

foo
   bar -> 01/02/05, 10000
   bar -> 04/06/10, 30023
foo
   bar -> 30/01/02, 23494

我想编写一个linq查询，该查询将为我返回一个不同的日期列表以及该日期的总和

And I want to write a linq query that will return me a distinct list of dates and the summed total for that date

可能是星期五，但我正在空白.

It may be that its friday, but I'm drawing a blank.

预先感谢

推荐答案

看起来像你想要的:

var query = from foo in list
            from bar in foo.Bars
            group bar.Value by bar.Date into dates
            select new { Date = dates.Key, Sum = dates.Sum() };

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