如何写这个linq [英] How to write this to linq

问题描述

任何人都可以帮我用延伸方法写这个给linq吗？



对于resule，我只需要月份和计数（CreatedDate）值< br $>

Can anyone could help me write this to linq using extension method??

For the resule, I only need the month and the count(CreatedDate) value

select YEAR(CreatedDate),MONTH(CreatedDate),count(CreatedDate) as number 
from Accounts
group by YEAR(CreatedDate),MONTH(CreatedDate)

推荐答案

我不确定你是否意味着你不需要年份结果或如果您也不想按年份分组。所以这里有一个版本的年份和一个没有：

I'm not sure if you mean you don't need the year in the result or if you also don't want to group by the year. So here's one version with the year and one without:

var result1 = Accounts.GroupBy(a => new { Year = a.CreatedDate.Year, Month = a.CreatedDate.Month })
                      .Select(g => new { Year = g.Key.Year, Month = g.Key.Month, Count = g.Count() });
                    //.ToList();  //optionally

var result2 = Accounts.GroupBy(a => a.CreatedDate.Month)
                      .Select(g => new { Month = g.Key, Count = g.Count() });
                    //.ToList();  //optionally

除了 Sascha [ ^ ]，您可以使用以下内容：

In addition to solution1 by Sascha[^], you can use something like this:

var result = Accounts.GroupBy(a => a.CreatedDate.ToString("yyyy-MM"))
                      .Select(g => new { Month = g.Key, Count = g.Count() });

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