linq to entity group by 時間


CreationTime是DateTime類型

group by 年/月/日/小時

group by 年

(from d in YourData.OrderBy(x => x.CreationTime)
 group d by new
 {
	 time = new { d.CreationTime.Year }
 } into g
 select new
 {
	 AverageValue = g.Average(p => p.Value),
	 CreationTimeStr = g.Key.time.Year,
	 MaxValue = g.Max(x => x.Value),
	 MinValue = g.Min(x => x.Value)
 }).ToList();

group by 小時

(from d in YourData.OrderBy(x => x.CreationTime)
 group d by new
 {
	 time = new { d.CreationTime.Year, d.CreationTime.Month, d.CreationTime.Day,d.CreationTime.Hour }
 } into g
 select new
 {
	 AverageValue = g.Average(p => p.Value),
	 CreationTimeStr = g.Key.time.Year + "-" + g.Key.time.Month + "-" + g.Key.time.Day+" "+g.Key.time.Hour+":00:00",
	 MaxValue = g.Max(x => x.Value),
	 MinValue = g.Min(x => x.Value)
 }).ToList();

其他類推

group by 半小時

group by 半小時=group by 30分鍾

(from d in YourData.OrderBy(x => x.CreationTime)
 group d by new
 {
	 time = new { d.CreationTime.Year, d.CreationTime.Month, d.CreationTime.Day,  d.CreationTime.Hour, Minute = (d.CreationTime.Minute / 30) * 30 }
 } into g
 select new
 {
	 Value = g.Average(p => p.Value),
	 CreationTimeStr = g.Key.time.Year + "-" + g.Key.time.Month + "-" + g.Key.time.Day + " " + g.Key.time.Hour + ":"+g.Key.time.Minute.ToString().PadRight(2,'0')+ ":00",
	 MaxValue = g.Max(x => x.Value),
	 MinValue = g.Min(x => x.Value)
 }).ToList();

group by 半月、半年等等可以類比

參考資料

Grouping by every n minutes


免責聲明!

本站轉載的文章為個人學習借鑒使用,本站對版權不負任何法律責任。如果侵犯了您的隱私權益,請聯系本站郵箱yoyou2525@163.com刪除。



 
粵ICP備18138465號   © 2018-2025 CODEPRJ.COM