linq分组和计数

弗洛林·M。

select  uc.adminid, count(*)
from Users uc
join UsersMessage ucm on uc.admincallid = ucm.admincallid
where uc.CallDate between '2016-08-01' and '2016-09-01' and ucm.type = 4
group by uc.adminid
order by count(*)

这是我尝试过的：

 public static Dictionary<int, int> ReturnSomething(int month)
        {

            Dictionary<int, int> dict = new Dictionary<int, int>();
            using (DataAccessAdapter adapter = new DataAccessAdapter())
            {
                LinqMetaData meta = new LinqMetaData(adapter);
                dict = (from uc in meta.Users
                        join ucm in meta.meta.UsersMessage on uc.AdminCallId equals ucm.AdminCallId 
                        where ucm.type == 4 && uc.CallDate.Month == month
                        group uc by uc.AdminId into g
                        select new { /* ???? adminid = g. */ }).ToDictionary(x => new Dictionary<int, int>(/* ????? x, x.Name*/));
            }

            return dict;
        }

我怎样才能实现我所需要的？

蒂姆·施密特（Tim Schmelter）

字典的键是的键，GroupBy值是的键Count()，因此您需要：

// ...
.ToDictionary(g => g.Key, g => g.Count()); // key is AdminCallId and value how often this Id occured

由于您已经问到如何订购降序：

您正在建立没有顺序的字典（嗯，它应该读为：它是不确定的）。因此，订购完全没有必要。为什么它是无序的？读这个

但是，如果您要创建其他东西，并且想知道如何订购，Count DESC可以使用以下命令：

from uc in meta.Users
join ucm in meta.meta.UsersMessage on uc.AdminCallId equals ucm.AdminCallId 
where ucm.type == 4 && uc.CallDate.Month == month
group uc by uc.AdminId into g
orderby g.Count() descending
select new { adminid = g.Key, count = g.Count() })

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