我每隔15分钟就会在PowerStringHistorys和PowerCombinerHistorys表中记录数据。我是LINQ的新手,我正在试图弄清楚如何创建一个查询,按小时对我的数据进行分组,并且该小时平均当前。这是我到目前为止所拥有的
TimeZoneInfo easternZone = TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time");
DateTime UTC_StartingDate = TimeZoneInfo.ConvertTimeToUtc(StartingDate, easternZone);
DateTime UTC_EndingDate = TimeZoneInfo.ConvertTimeToUtc(EndingDate, easternZone);
var FirstQ = from p in db.PowerStringHistorys
join t in db.PowerStrings on p.string_id equals t.id
join u in db.PowerCombiners on t.combiner_id equals u.id
join s in db.PowerCombinerHistorys on p.recordTime equals s.recordTime
where p.recordTime >= UTC_StartingDate
where p.recordTime <= UTC_EndingDate
select new
{
Combiner = u.id,
Current = p.current,
RecordTime = p.recordTime,
Voltage = s.voltage
};
现在我需要按组合器和小时进行分组,这样我就可以平均电流并获得指定日期范围内每小时的每个组合器的kwh。
我需要以某种方式在查询中应用这个简单的公式: (平均瓦/小时)/ 1000 = Kwh
所以我将以下面的内容结束。任何帮助将不胜感激。
Combiner 1 03/19/2012 1:0:0 1.85 Kwh
Combiner 1 03/19/2012 2:0:0 1.98 Kwh
Combiner 1 03/19/2012 3:0:0 2.05 Kwh
Combiner 1 03/19/2012 4:0:0 2.11 Kwh
Combiner 1 03/19/2012 5:0:0 2.01 Kwh
Combiner 1 03/19/2012 6:0:0 1.96 Kwh
Combiner 1 03/19/2012 7:0:0 1.85 Kwh
Combiner 2 03/19/2012 1:0:0 1.77 Kwh
Combiner 2 03/19/2012 2:0:0 1.96 Kwh
Combiner 2 03/19/2012 3:0:0 2.03 Kwh
Combiner 2 03/19/2012 4:0:0 2.11 Kwh
Combiner 2 03/19/2012 5:0:0 2.02 Kwh
Combiner 2 03/19/2012 6:0:0 1.98 Kwh
Combiner 2 03/19/2012 7:0:0 1.83 Kwh
Combiner 3 03/19/2012 1:0:0 1.77 Kwh
Combiner 3 03/19/2012 2:0:0 1.96 Kwh
Combiner 3 03/19/2012 3:0:0 2.03 Kwh
Combiner 3 03/19/2012 4:0:0 2.11 Kwh
Combiner 3 03/19/2012 5:0:0 2.02 Kwh
Combiner 3 03/19/2012 6:0:0 1.98 Kwh
Combiner 3 03/19/2012 7:0:0 1.83 Kwh
修改
以上是我原来的问题。在处理了我收到的两条建议后,我最终得到了下面显示的代码。现在我只是将日期和总Kwhs返回到视图中。我计划将stringGroupedKwhlist列表抛出到HighChart中,以便用户查看并将firstQ查询结果抛出到Telerik网格中,以便用户对其进行过滤/排序/分组,以便他们可以处理详细信息。虽然代码确实有效并产生我期望的结果,但我不确定它是否有效。由于我必须循环使用foreach,我猜测一旦获得大量数据,它可能会变慢。有没有更有效的方法来处理这个?
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web.Mvc;
using AESSmart.Models;
namespace AESSmart.Controllers
{
public class StringKwh
{
public int CombinerID;
public int StringID;
public DateTime Interval;
public Double KWH;
public StringKwh(int combiner, int stringid, DateTime interval, double kwh)
{
CombinerID = combiner;
StringID = stringid;
Interval = interval;
KWH = kwh;
}
}
public class HomeController : Controller
{
private readonly AESSmartEntities db = new AESSmartEntities();
public ActionResult Index()
{
//REPRESENTS DATE RANGE FOR A FULL DAY
DateTime startingDate = new DateTime(DateTime.Now.Year, DateTime.Now.Month, DateTime.Now.Day, 0, 0, 1);
DateTime endingDate = new DateTime(DateTime.Now.Year, DateTime.Now.Month, DateTime.Now.Day, 23, 59, 59);
TimeZoneInfo easternZone = TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time");
DateTime utcStartingDate = TimeZoneInfo.ConvertTimeToUtc(startingDate, easternZone);
DateTime utcEndingDate = TimeZoneInfo.ConvertTimeToUtc(endingDate, easternZone);
var firstQ = from p in db.PowerStringHistorys
from s in db.PowerCombinerHistorys
join t in db.PowerStrings on p.string_id equals t.id
join u in db.PowerCombiners on t.combiner_id equals u.id
where p.recordTime == s.recordTime
where p.recordTime >= utcStartingDate
where p.recordTime <= utcEndingDate
select new
{
Combiner = u.id,
StringId = p.string_id,
Current = p.current,
RecordTime = p.recordTime,
Voltage = s.voltage
};
var groups = firstQ.ToList().GroupBy(q => new
{
q.Combiner,
q.StringId,
Date = q.RecordTime.Date,
Hour = q.RecordTime.Hour
});
List<StringKwh> stringGroupedKwhlist = new List<StringKwh>();
foreach (var group in groups)
{
stringGroupedKwhlist.Add(new StringKwh(
group.Key.Combiner,
group.Key.StringId,
new DateTime(group.Key.Date.Year, group.Key.Date.Month, group.Key.Date.Day, group.Key.Hour, 0, 0),
group.Average(g => g.Voltage * g.Current) / 1000d
));
}
var groupCombiner = stringGroupedKwhlist.GroupBy(q => new { q.CombinerID });
double myTotalKwh = 0;
foreach (var combinerGroup in groupCombiner)
{
myTotalKwh = Math.Round(combinerGroup.Sum(g => g.KWH), 3);
}
ViewBag.LifeTimeGeneration = myTotalKwh;
ViewBag.myUTCStartDate = utcStartingDate;
ViewBag.myUTCEndDate = utcEndingDate;
return View();
}
public ActionResult About()
{
return View();
}
}
}
答案 0 :(得分:11)
这可能会让你开始:
// Group by combiner ID, date, and hour
var groups = FirstQ.ToList()
.GroupBy(q => new
{ q.Combiner, Date = q.RecordTime.Date, Hour = q.RecordTime.Hour });
foreach (var group in groups)
{
var combinerId = group.Key.Combiner;
var interval = new DateTime(group.Key.Date.Year, group.Key.Date.Month, group.Key.Date.Day, group.Key.Hour, 0, 0);
// power = voltage * current
var kwh = group.Average(g => g.Voltage * g.Current) / 1000d;
}
答案 1 :(得分:2)
尝试使用select
group
替换by
,如下所示:
TimeZoneInfo easternZone = TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time");
DateTime UTC_StartingDate = TimeZoneInfo.ConvertTimeToUtc(StartingDate, easternZone);
DateTime UTC_EndingDate = TimeZoneInfo.ConvertTimeToUtc(EndingDate, easternZone);
var FirstQ = from p in db.PowerStringHistorys
join t in db.PowerStrings on p.string_id equals t.id
join u in db.PowerCombiners on t.combiner_id equals u.id
join s in db.PowerCombinerHistorys on p.recordTime equals s.recordTime
where p.recordTime >= UTC_StartingDate
where p.recordTime <= UTC_EndingDate
group new
{
Combiner = u.id,
Current = p.current,
RecordTime = p.recordTime,
Voltage = s.voltage
}
by new
{
Combiner = u.id,
Date = p.RecordTime.Date,
Hour = p.RecordTime.Hour
};