使用linq C#从数据表中选择整个重复行 [英] Select entire duplicate row from datatable with linq c#

问题描述

我可以得到它来返回单列，但是我似乎无法弄清楚如何获得它来给我整行而不是仅仅给列值.

I can get it to return the single column, but I can't seem to figure out how to get it to give me the entire row instead of just the column values.

帮助！

它应该返回的字段是VDMList和Table.

the fields it should return are, VDMList and Table.

var duplicates = dt.AsEnumerable()
    .Select(dr => dr.Field<string>("VMDList"))
    .GroupBy(x => x)
    .Where(g => g.Count() > 1)
    .Select(g => g.Key)
    .ToList();


columns of DT Table, VDMList
output is
4  | 02,2
12 | 03,3
15 | 02,2

推荐答案

以下查询将为重复的VMDList行返回group中的first项.请注意，没有选择first项目的条件.它可以是任何random行.

Following query will return first item in the group for rows with duplicate VMDList. Note that there is no criteria for selecting the first item. It can be any random row.

var duplicates = dt.AsEnumerable()
    .GroupBy(dr => dr.Field<string>("VMDList"))
    .Where(g => g.Count() > 1)
    .Select(g => g.First())
    .ToList();

要返回所有重复的行，请使用 SelectMany

To return all rows that have duplicates, Use SelectMany

var allDuplicates = dt.AsEnumerable()
    .GroupBy(dr => dr.Field<string>("VMDList"))
    .Where(g => g.Count() > 1)
    .SelectMany(g => g)
    .ToList();

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