多列到行

Question

Raw data
我在数据表中的数据按第一个图像，而是想将我的数据表或创建新的输出是在第二图象一个新的DataTable

   var reportData = (from C in Table1 
            join LC in Table2 on C.Id equals LC.Id 
            select new { C.Id, C.User, LC.Phy, LC.Che, LC.Bio, LC.Math }).ToList(); 

       foreach (var item in reportData) 
       { 

        lstLc.Add(new Launch() { Username= item.User, Phy = item.Phy, Che = item.Che, Bio = item.Bio, Math = item.Math }); 
     } 

原始数据：Output needed

User Phy Che Bio Math 
A  12  20  16  10 
B  15  19  18  20 
C  13  17  11  18 

输出需要..

User Type value 
A  Phy  12 
A  Che  20 
A  Bio  16 
A  Math 10 
B  Phy  15 
B  Che  19 
B  Bio  18 
B  Math 20 
C  Phy  13 
C  Che  17 
C  Bio  11 
C  Math 18 

Answer 1

您可以使用union这样的：

SELECT User, Type, value FROM (
    SELECT User, 'Phy' AS 'Type', Phy AS 'value' FROM table1 
    UNION 
    SELECT User, 'Che' AS 'Type', Che AS 'value' FROM table1 
    UNION 
    SELECT User, 'Bio' AS 'Type', Bio AS 'value' FROM table1 
    UNION 
    SELECT User, 'Math' AS 'Type', Math AS 'value' FROM table1 
) AS t 
ORDER BY User 

在LINQ，你可以做这样的事情：

var list = entity.Select(e => new { User = e.User, Type = "Phy", value = e.Phy }) 
    .Union(entity.Select(e => new { User = e.User, Type = "Che", value = e.Che })) 
    .Union(entity.Select(e => new { User = e.User, Type = "Bio", value = e.Bio })) 
    .Union(entity.Select(e => new { User = e.User, Type = "Math", value = e.Math })) 
    .OrderBy(e => e.User); 

编辑你的代码改成这样：

var repFlatData = (from C in Table1 
        join LC in Table2 on C.Id equals LC.Id 
        select new { C.Id, C.User, LC.Phy, LC.Che, LC.Bio, LC.Math }).ToList(); 

var reportData = repFlatData.Select(e => new { User = e.User, Type = "Phy", value = e.Phy }) 
      .Union(repFlatData.Select(e => new { User = e.User, Type = "Che", value = e.Che })) 
      .Union(repFlatData.Select(e => new { User = e.User, Type = "Bio", value = e.Bio })) 
      .Union(repFlatData.Select(e => new { User = e.User, Type = "Math", value = e.Math })) 
      .OrderBy(e => e.User); 

foreach (var item in reportData) { 
    lstLc.Add(new Launch() { Username= item.User, Type = item.Type, Value = item.Value }); 
} 

当然，您需要将您的Launch类更改为只有列（用户名，类型，值）。