linq + groupby-在选择查询中添加字段 [英] linq + groupby - add fields in select query

问题描述

问题:我们可以对LINQ中的多个字段进行分组吗? 当前-我有linq这样的东西

q = q.GroupBy(c => c.Id)
     .Select(g => new View
                  {
                      Id = g.Key,
                      ENAME= string.Join(",", g.Select(x => x.CaseApprover).ToList())
                  });

我想用多个字段分组，例如

q = q.GroupBy(c => c.Id, c.name,c.age,c.dob) 

还要如何将它们放入选择查询中?这样我也将在选择查询中获得新添加的字段.

解决方案

尝试一下:

q = q.GroupBy(c => new { c.Id, c.name,c.age,c.dob })
    .Select(g => new
    {
        Id = g.Key.Id,
        ENAME= string.Join(",", g.Select(x => x.CaseApprover).ToList()),
        Name = g.Key.name,
        Age = g.Key.age,
        Dob = g.Key.dob,
    });

这将返回一个匿名类型，如果您想在View类中添加这些字段，只需添加它们即可.

question : can we made groupby to multiple fields in LINQ Currently - i have linq something like this

q = q.GroupBy(c => c.Id)
     .Select(g => new View
                  {
                      Id = g.Key,
                      ENAME= string.Join(",", g.Select(x => x.CaseApprover).ToList())
                  });

i wanted to group by with multiple fields something like

q = q.GroupBy(c => c.Id, c.name,c.age,c.dob) 

also how to put them in select query? such that i will get the newly added fields in select query also.

解决方案

Try this:

q = q.GroupBy(c => new { c.Id, c.name,c.age,c.dob })
    .Select(g => new
    {
        Id = g.Key.Id,
        ENAME= string.Join(",", g.Select(x => x.CaseApprover).ToList()),
        Name = g.Key.name,
        Age = g.Key.age,
        Dob = g.Key.dob,
    });

This will return an anonymous type, if you want these fields in your View class, just add them.

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