Question

有人可以为以下内容编写LINQ查询

鉴于以下数据，我需要以下内容每周得分最高的玩家，如果他们赢得超过一周，他们的数量。如果在一周内得分达到最高分，那么每个玩家得到一个计数。示例数据包括这种情况

Week   Player         Points 
1      Steve            35 
1      Mark             29 
1      John             26 
2      John             23 
2      Mark             21 
2      Steve            21 
3      Mark             42 
3      John             42 
3      Steve            19 
4      Pete             28 
4      John             16 
4      Steve            14 
4      Mark             12

结果将是

Player         Count
Steve            1
John             2
Mark             1
Pete             1

Answer 1

我可能会把它分成两个步骤 - 这实际上并不意味着任何事情都会被更早地执行，但它更容易理解。

// For each week, yield a sequence of winning results
var winningResultsByWeek = from result in results
                           group result by result.Week into week
                           let winningScore = week.Max(x => x.Points)
                           select week.Where(x => x.Points == winningScore)

var winsPerPlayer = from winningResults in winningResultsByWeek
                    from winningResult in winningResults
                    group winningResult by winningResult.Player into winsByPlayer
                    select new { Player = winsByPlayer.Key,
                                 Count = winsByPlayer.Count() };

命名在这里非常重要 - 希望通过拼写出来我已经明白了。我确信当然还有其他方法可以做到，但这是我想到的最清楚的方法。

LINQ Group和Count with Max

1 个答案: