Question

我有像

这样的结构

ID  Description Principal   Interest    Total
123 Paid        100          150        250
    Balance     50           50         100
    Total        ?            ?           ?
124 Paid        100          150        250
    Balance     50           50         100
    Total        ?            ?           ?

班级：

public class APIBillingHistory
{
    public List<APIBillingHistoryDetails> BillingHistoryDetails;
}

public class APIBillingHistoryDetails
{
    public string BillId;
    public string Description;
    public Decimal Principal;
    public Decimal Interest;
    public Decimal Total;
}

我想为每个ID 的每列加总值。因此，在上面的示例中，Total的ID 123的Principal同样为150，Interest 200。我在这里检查了这个解决方案How to create Total column and Total row using LINQ但是无法得到它。

代码：

responseObj = new APIBillingHistory
{
    BillingHistoryDetails = billingHistory.BillingHistoryDetails
            .GroupBy(detail => new { detail.BillId, detail.Description})
            .Select(group => new APIBillingHistoryDetails
            {
                BillId = group.Key.BillId,
                Description = group.Key.Description,
                Principal = group.Sum(t => t.Principal),
                Interest = group.Sum(t => t.Interest),
                Total = group.Sum(t => t.Principal) + group.Sum(t => t.Interest)
            }).Concat(new APIBillingHistoryDetails
            {
                Description = "Total",
                /*  Not sure what to write over here */
            })
};

编辑：

澄清我想要实现的目标：

我的源记录列表不包含“总计”列和＆amp; “总计”排。我想手动添加它。
我能够弄清楚如何添加包含值总和的“总计”列。
Principal＆amp; Interest将包含decimal格式的值。
ID列是一个整数。我想显示每个ID
Principal＆amp;的值Interest是基于ID汇总计算的，在计算之后，只会显示Total行。

任何建议？

Answer 1

您无法使用Concat并参考以前的数据。您需要使用SelectMany：

BillingHistoryDetails = billingHistory.BillingHistoryDetails
    .GroupBy(detail => detail.BillId)
    .SelectMany(bg => bg.Concat(new[] { new APIBillingHistoryDetails {
        BillId = bg.First().BillId,
        Description = "Total",
        Principal = bg.Sum(b => b.Principal),
        Interest = bg.Sum(b => b.Interest),
        Total = bg.Sum(b => b.Total)
    } }));

Answer 2

假设当前数据

BillId Description Principal   Interest
123    Paid        100          150    
123    Balance     50           50     
124    Paid        100          150     
124    Balance     50           50

然后只按身份分组，通过总结分组属性来创建总对象，将描述设置为＆＃34; Total＆＃34; 。

var totalsObj = new APIBillingHistory {
    BillingHistoryDetails = billingHistory.BillingHistoryDetails
           .GroupBy(detail => detail.BillId)
           .Select(g => new APIBillingHistoryDetails {
             BillId = g.Key,
             Description = "Total",
             Principal = g.Sum(detail => detail.Principal),
             Interest = g.Sum(detail => detail.Interest),
             Total = g.Sum(detail => detail.Principal) + g.Sum(detail => detail.Interest)
           }).ToList()
};

和totalsObj.BillingHistoryDetails可能需要输出

在计算之后，只显示总行数。

BillId Description Principal   Interest    Total
123    Total       150         200         350
124    Total       150         200         350

使用cq中的linq计算列的总和

2 个答案: