c# - LINQ嵌套字典总结

Question

字典 >

2015/6/1 10:30  table1  300,
                table2  600

2015/6/1 11:25  table1  200

2015/6/2 10:25  table1  200,
                table2  700

如何得到这些汇总结果

字典 >

2015/6/1   table1  500,
           table2  600

2015/6/2   table1  200,
           table2  700

Answer 1

您需要使用 SelectMany 来展平您的内部字典之后可以申请GroupBy首先在 DateTime 上(字典中的 Key)，然后在结果中您需要再次按 tables 分组。最后，您可以将输出投影为 Dictionary。这是完整的代码:-

Dictionary<DateTime,Dictionary<string,double>> result = 
                      data.SelectMany(x => x.Value, (key, obj) => new { key, obj })
                          .GroupBy(x => new { Date = x.key.Key.Date })
                          .Select(x => new
          {
              Date = x.Key.Date,
              Output = x.GroupBy(z => z.obj.Key)
                 .Select(t => new { Table = t.Key, Sum = t.Sum(m => m.obj.Value) })
                 .ToDictionary(d => d.Table, d => d.Sum)
          }).ToDictionary(x => x.Date, x=> x.Output);

Working Fiddle.