有组LINQ查询通过 [英] Linq query having group by

问题描述

RowNum IMAGEID     SCANEDATE                COUNT
1      10000131    2012-07-04 00:00:00.000  1
2      10002626    2012-08-03 00:00:00.000  1
3      10003348    2012-09-06 00:00:00.000  1
4      10003589    2012-09-15 00:00:00.000  8
5      10003590    2012-05-15 00:00:00.000  8
6      10003591    2012-04-15 00:00:00.000  8
7      10003592    2012-03-15 00:00:00.000  8
8      10003595    2012-02-15 00:00:00.000  8
9      10003596    2012-09-15 00:00:00.000  8
10     10003598    2012-09-15 00:00:00.000  8
11     10003599    2012-09-15 00:00:00.000  8

我上面的数据表上，我需要申请LINQ查询获取
结果如下：

I have above datatable on which I need to apply linq query for getting result as follows

1），具有相同日期的所有图像ID应该在同一个单元格上市（，
分离式）和计数列应具有每个日期的的计
各无。图像IDS

1) All images ids having same date should be listed in same cell(, seperated), and the count column should have the count of each date's respective no. of image ids

 Scan Date   Image ID  Count


      11/27/2007 1001529,1001530,1001531,1001532,1001533,1001534,1001537,1001538,1001539,1001540,1001542    11

      11/20/2008 1002501,1002502,1002503,1002504,1002505,1002506,1002507,1002508,1002509,1002510,1002511,1002512,1002513,1002514,1002515,1002516,1002517,1002518,1002519,1002520,    20

      7/5/2011   1015237,1015238    2

      7/6/2011   1015248,1015249,1015259,1015260,1015286,1015287,1015288,1015289,1015290,1015291,1015292,1015293,1015294,1015295,1015296,1015297,1015347,1015348,1015358,1015359,    32
      1015370,1015371,1015381,1015382,1015396,1015397,1015410,1015411,1015412,1015413,1015429,1015430

      7/7/2011   1015444,1015445    2

请提供给我的查询做以上。

Please provide me the query for doing the above.

推荐答案

由SCANEDATE场小组表行。然后通过选择扫描日期（组键），加入所有图像ID添加到字符串，并获得行计数的一组项目在每一组行：

Group table rows by SCANEDATE field. Then project each group of rows by selecting scan date (key of group), joining all images ids into string, and getting count of rows in a group:

table.AsEnumerable()
     .GroupBy(r => r.Field<DateTime>("SCANEDATE"))
     .Select(g => new {
          ScanDate = g.Key,
          Ids = String.Join(",", g.Select(r => r.Field<int>("IIMAGEID"))),
          Count = g.Count()
      });

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