Question

假设我有两个类似

的列表

      ID | IsChipCollected | IsShirtCollected | IsPackCollected
A     0                 1                  0                 1
      1                 0                  1                 0
      2                 0                  0                 1      


B     0                 0                  1                 0
      1                 0                  0                 1
      2                 1                  1                 1

基本上我需要比较和合并2个列表，如果某个标志在B中设置为真，我应该选择它而不是A

我知道如何通过一个专栏实现这一目标，但我正在努力绕着我的脑袋在2列以上的场景中做到这一点

  var result = A.Concat(B)
        .GroupBy(x => x.Id)
        .Select(g => g.OrderByDescending(x => x.IsShirtCollected).First())

如果我在此方面取得任何进展，我会更新我的代码示例，（因为我目前仍在攻击：P）

预期结果

     ID | IsChipCollected | IsShirtCollected | IsPackCollected
      0                 1                  1                 1
      1                 0                  1                 1
      2                 1                  1                 1

Answer 1

var result = A.Concat(B)
        .GroupBy(x => x.Id)
        .Select(g => new {//or new <A and B's generic type>, then change the underCode with proper case
             id = g.Key,
             isShipCollected = g.Max(m => m.IsChipCollected),
             isShirtCollected = g.Max(m => m.IsShirtCollected),
             isPackCollected = g.Max(m => m.IsPackCollected)
    });

修改

遵循Servy（好）的想法（将1/0更改为布尔值）

var result = A.Concat(B) .GroupBy(x => x.Id) .Select(g => new { id = g.Key, isShipCollected = g.Any(m => m.IsChipCollected == 1), isShirtCollected = g.Any(m => m.IsShirtCollected == 1), isPackCollected = g.Any(m => m.IsPackCollected == 1) });

Answer 2

不确定它是否比concat / groupby更快/更慢，但从技术上讲，您正在执行的操作是Join，因此在实际执行该连接的可读性方面更有意义。

var query = listA.Join(listB, item => item.ID, item => item.ID,
    (a, b) => new
    {
        ID = a.ID,
        IsChipCollected = a.IsChipCollected | b.IsChipCollected,
        IsShirtCollected = a.IsShirtCollected | b.IsShirtCollected,
        IsPackCollected = a.IsPackCollected | b.IsPackCollected,
    });

始终在LINQ语句组中选择true / higher值（多列）

2 个答案: