根据时间求平均值
一列日期TestDate,一列时间TestTime,一列数据Eta,求每小时Eta的平均值.

[解决办法]

C# code

var query = from x in data            select (x.TestDate + x.TestTime - (data.Where(y => y.TestDate + y.DayeTime < x.TestDate + x.DayeTime).OrderBy(y => y.TestDate + y.DayeTime).Select(y => y.TestDate + y.DayeTime).Last()) / x.Eta;
[解决办法]
string sql="select AVG(Eta) as 平均数 datepart('h',TestTime) from table group by datepart('h',TestTime)"