无法获得通过LINQ

Question

结果我有这样

Id TagNo FromBay FromPanel FDevice FRef 
    1 1000 A  B  C1  1 
    2 1000 A  B  C1  2 
    3 1000 A  B  C1  R2 
    4 1000 A  B  C2  2 
    5 1000 A  B  C2  3 
    6 1000 A  B  C2  4 

我想有这个

 TagNo FromBay FromPanel FDevice FRef 
    1000 A  B  C1  1 
             2 
             R2 
           C2  2 
             3 
             4 

值的表是一个DataTable名为cableDataTable

var rows = cableDataTable.AsEnumerable() 
          .Select(x => new 
          { 
           TagNo = x.Field<string>("TagNo"), 
           FromBay = x.Field<string>("FromBay"), 
           FromPanel = x.Field<string>("FromPanel"),   
           FDevice = x.Field<string>("FDevice"),         

           FRef = x.Field<string>("FRef")                 
           }); 

    var results = rows.GroupBy(row => new { row.FromBay, row.FromPanel, row.TagNo }) 
         .OrderBy(g => g.Key.FromBay) 
         .ThenBy(g => g.Key.FromPanel) 
         .SelectMany(g => g.OrderBy(row => row.TagNo) 
         .Select((x, i) => 
           new 
           {           
            TagNo = (i == 0) ? x.TagNo.ToString() : "",          
            FromBay = (i == 0) ? x.FromBay : "", 
            FromPanel = (i == 0) ? x.FromPanel : "", 
            FDevice = (i == 0) ? x.FDevice : "", 
            FRef = x.FRef,           
           })).ToList(); 

但我得到这个

     TagNo FromBay FromPanel FDevice FRef 
         1000 A  B  C1  1 
                 2 
                 R2 
                 2 
                 3 
                 4 

我在一个论坛中发现了这个问题，但我不知道该怎么做。选择（（x，i））很激动，我怎样才能得到我需要的结果。 我找不到问题

Answer 1

我给你写了一个以分层方式获取数据的例子，我希望这就是你要找的。

var results = rows.GroupBy(row => new {row.FromBay, row.FromPanel, row.TagNo}) 
     .Select(x => new 
      { 
       x.Key.TagNo, 
       x.Key.FromBay, 
       x.Key.FromPanel, 
       Devices = 
         rows.GroupBy(
          row => new {row.FromBay, row.FromPanel, row.TagNo, row.FDevice}) 
          .Where(f => f.Key.TagNo == x.Key.TagNo) 
          .Where(f => f.Key.FromBay == x.Key.FromBay) 
          .Where(f => f.Key.FromPanel == x.Key.FromPanel) 
          .Select(y => new 
           { 
            y.Key.FDevice, 
            FRef = 
              rows.Where(r => r.TagNo == y.Key.TagNo) 
               .Where(r => r.FromBay == y.Key.FromBay) 
               .Where(r => r.FromPanel == y.Key.FromPanel) 
               .Where(r => r.FDevice == y.Key.FDevice) 
               .Select(i => i.FRef) 
               .ToList() 
           }).ToList() 
      }).ToList(); 

Answer 2

试试这个：

var results = rows.GroupBy(row => new { row.TagNo, row.FromBay, row.FromPanel}) 
        .OrderBy(g => g.Key.TagNo) 
        .ThenBy(g => g.Key.FromBay) 
        .ThenBy(g => g.Key.FromPanel) 
        .Select((g,i) => new { 
            key = g.Key,i,    
            sub = g.GroupBy(x=>x.FDevice).OrderBy(g=>g.Key) 
              .Select(g=>g.Select((x,j)=>new{x,j})) 
            })        
        .SelectMany(e=> e.sub, (e,c)=> new { 
           TagNo = e.i == 0 ? e.key.TagNo.ToString() : "", 
           FromBay = e.i == 0 ? e.key.FromBay : "", 
           FromPanel = e.i == 0 ? e.key.FromPanel : "", 
           FDevice = c.j == 0 ? c.x.FDevice : "", 
           FRef = c.x.FRef, 
           });