LINQ合并结果按行 [英] LINQ Merging results in rows

问题描述

我有一个LINQ查询，它返回一组行.结构是:

I have a LINQ query which returns a set of rows. The structure is:

NAME,    col1, col2, col3, col4
name1     1    null  null  null
name1    null   1    null  null
name1    null  null   1     1 

因此，我希望包含一行内容

As a result I want to have one row containing

name1     1     1     1     1

因此，我想按名称对这些结果进行分组并合并(总和?)其他列，因此，如果我在一列中的某行中不存在null-我将收到除null之外的任何内容.

So I want to group those results by name and merge (sum?) the other columns so if I have not null in one of the rows in a column - I will receive anything except null.

感谢帮助！

推荐答案

class MyObj
{
    public string Name { get; set; }
    public int? Col1 { get; set; }
    public int? Col2 { get; set; }
    public int? Col3 { get; set; }
    public int? Col4 { get; set; }
}

List<MyObj> l = new List<MyObj> {
    new MyObj {Name = "name1", Col1 = 1 },
    new MyObj {Name = "name1", Col2 = 1 },
    new MyObj {Name = "name1", Col3 = 1 },
    new MyObj {Name = "name1", Col4 = 1 }
};

var qry = from o in l
          group o by o.Name into g
          select new
          {
              Name = g.Key,
              Col1 = g.Any(e => e.Col1.HasValue) ? (int?)1 : null,
              Col2 = g.Any(e => e.Col2.HasValue) ? (int?)1 : null,
              Col3 = g.Any(e => e.Col3.HasValue) ? (int?)1 : null,
              Col4 = g.Any(e => e.Col4.HasValue) ? (int?)1 : null
          };

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