问题描述

我有以下动态列表

Crew   NameSurname  Period  Result
ABC    John DOE     Q1      54,09
ABC    John DOE     Q2      59,57
ABC    John DOE     Q3      62,11

我怎样才能在 linq 中得到这个结果.

How can I get this result with in linq.

Crew   NameSurname  Q1      Q2      Q3
ABC    John DOE     47,51   47,51   51,46

我试过这种方法，但我无法得到结果

I've tried this way but I couldn't get the result

List.GroupBy(c => c.PersonnelID)
     .Select(g => new
     {
         PersonnelID = g.Key,
         Period1 = g.Where(c => c.Period == 1).Sum(c => c.Result),
         Period2 = g.Where(c => c.Period == 2).Sum(c => c.Result),
         Period3 = g.Where(c => c.Period == 3).Sum(c => c.Result)
     });

推荐答案

你可以这样做:

var results = Data.GroupBy(l => new { l.Crew, l.NameSurname});
    .SelectMany( (key, g) => 
                 new 
                 { 
                     Crew = Key.Crew,
                     NameSurname = Key.NameSurname,  
                     groups = g 
                 });

var pivoted = new List<PivotedCrew>();

foreach(var item in results)
{
    pivoted.Add( 
        new PivotedCrew
        {
            Crew  = item.Crew,
            NameSurname = item.NameSurname,
            Q1 = item.groups.Where(x => x.Period == "Q1")
                     .FirstOrDefault().value,
            Q2 = item.groups.Where(x => x.Period == "Q2")
                     .FirstOrDefault().value,
            Q3 = item.groups.Where(x => x.Period == "Q3")
                     .FirstOrDefault().value
        });
}

但是您需要定义一个新类.比如:

But you will need to define a new class. Something like:

public class PivotedCrew
{
    public string Crew Id {get; set;}
    public string NameSurname {get; set;}
    public string Q1 {get; set;}   
    public string Q2 {get; set;}   
    public string Q3 {get; set;}   
}

这篇关于在 linq 中使用数据透视表的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！