Linq 求和汇总

码拜

8年 ago

下面是本人分组时候的求和，现在本人想不要分组，仅求于 Qty1 ~ Qty 15，
讨教 Linq 怎么样写？
var q = from p in dtQtyDetail.AsEnumerable() //Linq Group By 求和汇总
group p by new
{
ColorID = p.Field<string>(“ColorID”),
VampMaterial = p.Field<string>(“VampMaterial”),
} into g
select new
{
ColorID = g.Key.ColorID,
VampMaterial = g.Key.VampMaterial,
Qty1 = g.Sum(p => p.Field<Int16>(“Qty1”)),
Qty2 = g.Sum(p => p.Field<Int16>(“Qty2”)),
Qty3 = g.Sum(p => p.Field<Int16>(“Qty3”)),
Qty4 = g.Sum(p => p.Field<Int16>(“Qty4”)),
Qty5 = g.Sum(p => p.Field<Int16>(“Qty5”)),
Qty6 = g.Sum(p => p.Field<Int16>(“Qty6”)),
Qty7 = g.Sum(p => p.Field<Int16>(“Qty7”)),
Qty8 = g.Sum(p => p.Field<Int16>(“Qty8”)),
Qty9 = g.Sum(p => p.Field<Int16>(“Qty9”)),
Qty10 = g.Sum(p => p.Field<Int16>(“Qty10”)),
Qty11 = g.Sum(p => p.Field<Int16>(“Qty11”)),
Qty12 = g.Sum(p => p.Field<Int16>(“Qty12”)),
Qty13 = g.Sum(p => p.Field<Int16>(“Qty13”)),
Qty14 = g.Sum(p => p.Field<Int16>(“Qty14”)),
Qty15 = g.Sum(p => p.Field<Int16>(“Qty15”)),
TotalQty = g.Sum(p => p.Field<Int32>(“TotalQty”))
};
相当于 SQL：
select
SUM(Qty1)[Qty1],SUM(Qty2)[Qty2],SUM(Qty3)[Qty3],……..
from 表
不分组求和多列

解决方案

group by本来就是Linq的东西，不用这个，估计很难
或可以放到datatable处理

select new这个匿名对象是编译产生的，假如你不计划用codedom或emit的话，只能硬写

引用:

Quote: 引用:
select new这个匿名对象是编译产生的，假如你不计划用codedom或emit的话，只能硬写

Linq 能分组求和，不太可能不分组了就求和不了了，只是本人不知道怎么写。

分组和求和有什么关系，不分组也能求和。

150

    var q = from p in dtQtyDetail.AsEnumerable()        
                        group p 1 into g
                        select new
                        { 
                            Qty1 = g.Sum(p => p.Field<Int16>("Qty1")),
                            Qty2 = g.Sum(p => p.Field<Int16>("Qty2")),
                            Qty3 = g.Sum(p => p.Field<Int16>("Qty3"))
                        };

finally you still using a “fake” group by

var q = from p in dtQtyDetail.AsEnumerable() //Linq Group By 求和汇总
group p by “A” into g
select new
{
ColorID = g.Key.ColorID,
VampMaterial = g.Key.VampMaterial,
Qty1 = g.Sum(p => p.Field<Int16>(“Qty1”)),
Qty2 = g.Sum(p => p.Field<Int16>(“Qty2”))
//……
};
分组依据放一个常量，这个组就是整个表本身，这样就是整个表Qty1、Qty2、Qty3……字段的总和了