Linq 用总和分组

Question

大家好，我有以下代码

var deptSalesQuery = from d in db.DashboardFigures
join s in outlets.Split(',').Select(x => int.Parse(x)) on d.OutletNo equals s
            where (d.TypeOfinformation == "DEPTSALES")                                
            select new DeptSales
                    {
                      Dn = (int)d.Number,                                                 
                      On = d.OutletNo,
                      Qs = (double)d.Value_4,
                      Se = (double)d.Value_2,
                      Si = (double)d.Value_3
                    };

我想要做的是将查询按“Dn”分组，即“d.Number”并返回 (double)d.Value_4、(double)d.Value_2、(double)d.Value_3 的总和。我看过论坛，有些人问过类似的问题，但由于某种原因，它对我不起作用。有人可以帮忙吗？

我已将代码更改为

var deptSalesQuery = from d in db.DashboardFigures
join s in outlets.Split(',').Select(x => int.Parse(x)) on d.OutletNo equals s
                                 where (d.TypeOfinformation == "DEPTSALES")
                                 group d by d.Number into newGroupedresult
                                 select new DeptSales
                                 {   

                                     Qs = (double)newGroupedresult.Sum(d => d.Value_4),
                                     Se = (double)newGroupedresult.Sum(d => d.Value_2),
                                     Si = (double)newGroupedresult.Sum(d => d.Value_3)
                                 };

但它不是分组，它显示的是单个记录。另外我通常有 Dn = D.Number，它不允许我放这个。

Answer 1

deptSalesQuery
.GroupBy(x => x.Number)
.Select(g => new 
             { 
                Dn = g.Key, 
                Sum = g.Sum(x => x.Value_2 + x.Value_3 + Value_4)
             });