SQL服務器日平均值

Question

什麼是獲得日常平均值的最佳方式。 的數據將每天2個值，例如：

Date    Value 
1/1/2012 4:00 10.00 
1/1/2012 16:00 11.00 
1/2/2012 4:00 11.22 
1/2/2012 16:00 13.55 
etc. 

Answer 1

Select CAST(DateColumn as date), AVG(Value) 
From Table 
Group By CAST(DateColumn as date) 

Answer 2

select date, avg(value) 
from yourTable 
group by date 

Answer 3

select 
cast(Date as date), 
avg(Value) 
from 
Table 
group by cast(Date as date)