C# 如何对实体框架中的列求和

how to sum a column in entity framework

提问by Dharmeshsharma

I am trying to sum a column and get details member wise

我正在尝试对一列求和并了解详细信息成员

My table data is

我的表数据是

id   membername     cost
1   a               100
2   aa              100
3   a               100
4   aa                0
5   b               100

---

---

In Entity Framework I try to sum cost column and get result like this

在实体框架中，我尝试对成本列求和并得到这样的结果

membername             totalcost
a                      200
aa                     100
b                      100

then I am doing this

然后我在做这个

var result = from o in db.pruchasemasters.Where(d => d.memberid == d.membertable.id && d.entrydate >= thisMonthStart && d.entrydate <= thisMonthEnd)
                     group o by new { o.membertable.members } into purchasegroup
                     select new
                     {
                         membername = purchasegroup.Key,
                         total = purchasegroup.Sum(s => s.price)
                     };

How do I read the results and is my code right or not?

我如何阅读结果，我的代码是否正确？

采纳答案by Vitalik

Something like that will work

像这样的东西会起作用

    var result = db.pruchasemasters.GroupBy(o => o.membername)
                   .Select(g => new { membername = g.Key, total = g.Sum(i => i.cost) });

    foreach (var group in result)
    {
        Console.WriteLine("Membername = {0} Totalcost={1}", group.membername, group.total);
    }