LINQ通过相应的时间字段查找最大/最小值

Question

我有一个气象站的数据记录表，从中查询结果到WPF ListBox。

表结构是：

• 日期
• 时间
• 临时
• rain_today
• 湿度
• 等

我有工作正常的查询：

var q = from c in db.Apr11log 
       group c by c.LogDate into g 
       orderby g.Key 
       select new 
       { 
        LogDate = g.Key, 
        MaxTemp = g.Max(c => c.Temp), 
        MinTemp = g.Min(c => c.Temp),            
        Rain = g.Max(c => c.Rain_today), 
       };  

不过，我想获得的最高温度和最低温度的相应时间，即

TimeMax = ..... 
TimeMin = ..... 

我GOOGLE和GOOGLE上搜索，但发现没有什么用处。

Answer 1

let maxTemp = c.Max(c=>c.Temp) 
let minTemp = c.Min(c=>c.Temp) 
select new { 
    LogDate = g.Key, 
    MaxTemp = maxTemp, 
    MinTemp = minTemp, 
    MaxTime = g.FirstOrDefault(c=>c.Temp = maxTemp).Time, 
    MinTime = g.FirstOrDefault(c => c.Temp = minTemp).Time, 
    Rain = g.Max(c => c.Rain_today), 
     };  

Answer 2

var q = from c in db.Apr11log 
     group c by c.LogDate into g 
     orderby g.Key 
     select new 
     { 
      LogDate = g.Key, 
      MaxRow = g.OrderByDescending(c => c.Temp).Select(c => new { c.LogDate, c.Temp }).First(), 
      MinRow = g.OrderBy(c => c.Temp).Select(c => new { c.LogDate, c.Temp }).First(), 
      Rain = g.Max(c => c.Rain_today), 
     }; 

或

var q = from c in db.Apr11log 
     group c by c.LogDate into g 
     orderby g.Key 
     let maxRow = g.OrderByDescending(c => c.Temp).First() 
     let minRow = g.OrderBy(c => c.Temp).First() 
     select new 
     { 
      LogDate = g.Key, 
      MaxTemp = maxRow.Temp, 
      MaxTempDate = maxRow.LogDate, 
      MinTemp = minRow.Temp, 
      MinTempDate = minRow.LogDate, 
      Rain = g.Max(c => c.Rain_today), 
     };