Question

我有一个带有列

的表结构

FeesNormal

FeesCustom

货币

现在我正在寻找按货币计算的SUM功能组。

例如20 USD + 30 EURO + 40 INR此表中的内容

如果FeesCustom＆gt;我还必须考虑这个场景。 0我必须忽略行的FeesNormal

样本日期和预期结果是这样的

[2016-05-30 08:16:00.934 UTC] Large Lookup Fast Random UInt: 273 ms
[2016-05-30 08:16:01.230 UTC] Large Lookup Fast Random: 294 ms
[2016-05-30 08:16:01.503 UTC] Large Lookup Optimized Random: 273 ms
[2016-05-30 08:16:01.837 UTC] Fastest Optimized Random Modded: 333 ms
[2016-05-30 08:16:02.245 UTC] Numbers: 408 ms
[2016-05-30 08:16:02.532 UTC] Large Lookup Parameterless Random: 287 ms
[2016-05-30 08:16:02.816 UTC] Large Lookup: 284 ms
[2016-05-30 08:16:03.145 UTC] Lookup Optimized Modded: 329 ms
[2016-05-30 08:16:03.486 UTC] Fastest Optimized Modded: 340 ms
[2016-05-30 08:16:03.824 UTC] Optimized Modded Const: 337 ms
[2016-05-30 08:16:04.154 UTC] Optimized Modded: 330 ms
[2016-05-30 08:16:04.524 UTC] Modded: 370 ms
[2016-05-30 08:16:05.700 UTC] Simple: 1176 ms
[2016-05-30 08:16:07.309 UTC] Another simple with HashSet: 1609 ms
[2016-05-30 08:16:09.774 UTC] Another Simple: 2465 ms
[2016-05-30 08:16:17.450 UTC] Option (Compiled) Regex: 7675 ms
[2016-05-30 08:16:34.090 UTC] Regex: 16640 ms
[2016-05-30 08:16:54.793 UTC] EndsWith: 20702 ms

我能够使用linq找到总和

  FeesNormal  FeesCustom  Currency
  10          0            USD   
  15          25           USD //in this case can ignore FeesNormal Since FeesCustom is more
  5           10           EUR //same for this row ignore FeesNormal
  10          0            EUR

Expected result  35 USD 20 EUR

Answer 1

在我看来，你只需要一个从“入场”到“有效费用”的预测，你可以总结 - 例如：

var result = source
    .GroupBy(x => x.Currency)
    .Select(g => new {
        Currency = g.Key,
        Total = g.Sum(x => x.FeesCustom > 0 ? x.FeesCustom : x.FeesNormal)
    });

这相当于：

var result = source
    .GroupBy(x => x.Currency,
             (key, values) => new {
                Currency = key,
                Total = values.Sum(x => x.FeesCustom > 0 ? x.FeesCustom : x.FeesNormal)
             });

或者之前进行转换：

 var result = source
     .Select(x => new {
         x.Currency,
         x.Fee = x => x.FeesCustom > 0 ? x.FeesCustom : x.FeesNormal
     })
     .GroupBy(x => x.Currency, x => x.Fee,
              (key, values) => new { Currency = key, Fee = values.Sum() });

Answer 2

使用查询语法：

var feeResult = (from fee in fee_list
                group fee by fee.Currency into groupResult
                select new
                {
                    Currency = groupResult.Key,
                    FinalFees = groupResult.Sum(f => f.FeesCustom > 0 ? f.FeesCustom : f.FeesNormal)
                }).ToList();

Answer 3

假设您有DataTable所提及的数据，您可以使用Linq

执行此操作

var result = table.AsEnumerable()        
     .GroupBy(x=> x.Field<string>("Currency"))
     .Select(x=> new
      {
          Currency = x.Key,
          Value = x.Sum(s=> Math.Max(s.Field<double>("FeesNormal"), s.Field<double>("FeesCustom "))),

      }      
      .ToList()

Linq Sum with group by

3 个答案: