实体框架按时间过滤数据

Question

对于这个问题，我感到很抱歉，但是我不能在DateTime花点时间。 例如：如果我的日期为"10.10.2016 7:00", 10.10.2016 10:00" ，则只需要输入时间在” 6:00“和” 8:00“之间的行。代码返回错误： "can not use TimeOfDay ",请帮助我

ds.TrafficJamMorning = (from row in orderQuery
                        where row.AcceptedTime.TimeOfDay >= new TimeSpan(6, 30, 0) &&
                        row.AcceptedTime.TimeOfDay <= new TimeSpan(9, 30, 0)
                        group row by row.AcceptedTime.Date
                        into grp
                        select new TrafficJamPeriodInfo
                        {
                             CurrentDateTime = grp.Key,
                             ReceptionCount = grp.Count(r => r.OrderOriginId == (int)OrderOrigin.Reception),
                             InternetCount = grp.Count(r => r.OrderOriginId == (int)OrderOrigin.Internet),
                             ExchangeSystemCount = grp.Count(r => r.OrderOriginId == (int)OrderOrigin.ExchangeSystem)
                        }).ToList();

Answer 1

linq提供程序不支持TimeOfDay ，并且它不知道如何将其解析为sql。 改用DbFunctions.CreateTime ：

还要在linq查询之前实例化时间跨度，因此您不必每次都实例化一个新对象

var startTime = new TimeSpan(6, 30, 0);
var endTime = new TimeSpan(9, 30, 0);

var result = (from row in orderQuery
              let time = DbFunctions.CreateTime(row.AcceptedTime.Hour, row.AcceptedTime.Minute, row.AcceptedTime.Second)
              where time  >= startTime &&
                    time  <= endTime
              group row by DbFunctions.TruncateTime(row.AcceptedTime) into grp
              select new TrafficJamPeriodInfo
              {
                   CurrentDateTime = grp.Key,
                   ReceptionCount = grp.Count(r => r.OrderOriginId == (int)OrderOrigin.Reception),
                   InternetCount = grp.Count(r => r.OrderOriginId == (int)OrderOrigin.Internet),
                   ExchangeSystemCount = grp.Count(r => r.OrderOriginId == (int)OrderOrigin.ExchangeSystem)
              }).ToList();

再次查看问题-如果您要检查的时间是2小时之间，请使用Hour属性（如果要检查Hour和Minues的话，这样写就Minues ，在这种情况下，我会提出我的第一个建议） ：

var result = (from row in orderQuery
              where row.AcceptedTime.Hour >= 6
                    row.AcceptedTime.Hour < 8
              group row by DbFunctions.TruncateTime(row.AcceptedTime) into grp
              select new TrafficJamPeriodInfo
              {
                   CurrentDateTime = grp.Key,
                   ReceptionCount = grp.Count(r => r.OrderOriginId == (int)OrderOrigin.Reception),
                   InternetCount = grp.Count(r => r.OrderOriginId == (int)OrderOrigin.Internet),
                   ExchangeSystemCount = grp.Count(r => r.OrderOriginId == (int)OrderOrigin.ExchangeSystem)
              }).ToList();

Answer 2

我有一个类似的问题。

您可以改为比较日期部分。

其中row.Year> s.Year && r.Month> s.Month && row.Day> s.Day

Answer 3

我在IQueryable上使用以下where子句：

var query = dbContext.GetAllItems().AsQueryable();

//... other filters

if(MusBeBetween6and8){
    query = query.Where(item => item.AcceptedTime.Hour > 6 && item.AcceptedTime.Hour < 8);
}

//... other filters

return query.ToList();

希望能帮助到你。 这也适用于Oracle + Odac。

Answer 4

ds.TrafficJamMorning = (from row in orderQuery
                        where 
                            DbFunctions.DiffMinutes( DbFunctions.TruncateTime(row.AcceptedTime), row.AcceptedTime) >= 6 * 60 + 30 &&
                            DbFunctions.DiffMinutes( DbFunctions.TruncateTime(row.AcceptedTime), row.AcceptedTime) <= 9 * 60 + 30
                        group row by DbFunctions.TruncateTime(row.AcceptedTime)
                        into grp
                        select new TrafficJamPeriodInfo
                        {
                            CurrentDateTime = grp.Key,
                            ReceptionCount = grp.Count(r => r.OrderOriginId == (int)OrderOrigin.Reception),
                            InternetCount = grp.Count(r => r.OrderOriginId == (int)OrderOrigin.Internet),
                            ExchangeSystemCount = grp.Count(r => r.OrderOriginId == (int)OrderOrigin.ExchangeSystem)
                        }).ToList();