我有一个气象站的数据记录表,我从中查询结果到WPF ListBox
。
表格结构为:
- 日期
- 时间
- 温度
- 雨天
- 湿度
- 等等
我有一个运行良好的查询:
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),
};
然而,我正在尝试获得最高温度和最低温度的相应时间,即
TimeMax = .....
TimeMin = .....
我在谷歌上搜索了又搜索,但没有发现任何有用的东西。
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),
};
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),
};