EF 按时、按天、按周、按月查询数据怎么实现

Question

//获取当天所有时间段的条件数据
for (int i = 0; i < 24; i++)
{
DateTime temp = new DateTime(endTime.Year, endTime.Month, endTime.Day, i, 0, 0);
int tag = temp.Hour;
flowWhere = (m) => m.WebInfo.Id == webId && m.DeviceType.Contains(device) && SqlFunctions.DateDiff("hh", temp, m.CurrentTime) == 0;
vifWhere = (m) => m.WebInfo.Id == webId && m.DeviceType.Contains(device) && SqlFunctions.DateDiff("hh", temp, m.AccessTime) == 0 || m.VisitSE == source || m.Address == territory;
TimeSpan ts = new TimeSpan(temp.Hour, 0, 0);
VisitorInfo model = new VisitorInfo();
model.Address = ts.ToString();
model.Age = tag;
se.Add(model);
VisitorInfo visitor = sm.GetHourByExpression(vifWhere, flowWhere);
UV.Add(visitor);
}
se = se.OrderBy(m => m.Address).ToList();
}

Answer 1

用不着DateDiff，因为EF直接支持将大于小于号翻译成对应的sql

var dt = DateTime.Now.AddDays(-7);

var query = 你的数据.Where(x => x.时间字段 > dt);

如果你是7天内每小时，代码如下
var query = 你的数据.Where(x => x.时间字段 > dt).GroupBy(x => new { x.时间字段.Month, x.时间字段.Day, x.时间字段.Hour });