如何在LINQ中将行转换为列

// 假设有一个包含学生姓名和科目成绩的学生成绩表
var studentScores = new List<StudentScore>
{
    new StudentScore { Name = "张三", Subject = "数学", Score = 90 },
    new StudentScore { Name = "张三", Subject = "英语", Score = 80 },
    new StudentScore { Name = "李四", Subject = "数学", Score = 85 },
    new StudentScore { Name = "李四", Subject = "英语", Score = 75 },
    new StudentScore { Name = "王五", Subject = "数学", Score = 95 },
    new StudentScore { Name = "王五", Subject = "英语", Score = 85 }
};

// 使用LINQ将行转换为列
var result = studentScores
    .GroupBy(s => s.Name) // 按照姓名分组
    .Select(g => new
    {
        Name = g.Key,
        MathScore = g.FirstOrDefault(s => s.Subject == "数学")?.Score, // 数学成绩列
        EnglishScore = g.FirstOrDefault(s => s.Subject == "英语")?.Score // 英语成绩列
    });

// 输出结果
foreach (var item in result)
{
    Console.WriteLine($"姓名：{item.Name}，数学成绩：{item.MathScore ?? 0}，英语成绩：{item.EnglishScore ?? 0}");
}