I want to list all sales, and group the sum by day.
Sales (saleID INT, amount INT, created DATETIME)
NOTE: I am using SQL Server 2005.
if you're using SQL Server,
dateadd(DAY,0, datediff(day,0, created))
will return the day created
for example, if the sale created on '2009-11-02 06:12:55.000',
dateadd(DAY,0, datediff(day,0, created))
return '2009-11-02 00:00:00.000'
select sum(amount) as total, dateadd(DAY,0, datediff(day,0, created)) as created
from sales
group by dateadd(DAY,0, datediff(day,0, created))