SQL Server в среднем за день

Question

Какой лучший способ получить среднесуточное значение.Данные будут иметь 2 значения в день, например:

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)