Linq to objects Linq到实体的合计和
我有以下疑问:Linq to objects Linq到实体的合计和,linq-to-objects,Linq To Objects,我有以下疑问: var query = (from o in orders group new { o.OrderDate, o.paymenttotal } by new { o.OrderDate.Value.Month, o.OrderDate.Value.Year } into grouping orderby grouping.Key.Month select new { grouping, totalPayment = grouping
var query = (from o in orders
group new
{
o.OrderDate,
o.paymenttotal
}
by new
{
o.OrderDate.Value.Month,
o.OrderDate.Value.Year
} into grouping
orderby grouping.Key.Month
select new
{
grouping,
totalPayment = grouping.Sum (g => g.paymenttotal)
});
query.Dump();
该查询工作得很好,它给出了每个月总计的明细,我想扩展查询以添加所有总计的总和,这样我就可以有一个“页脚总计”
希望这是有意义的。您正在寻找的概念在SQL中称为带汇总的
。在LINQ中有一个实现