SQL query to group by day

Question

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.

Answer 1

actually this depends on what DBMS you are using but in regular SQL convert(varchar,DateColumn,101) will change the DATETIME format to date (one day)

so:

SELECT 
    sum(amount) 
FROM 
    sales 
GROUP BY 
    convert(varchar,created,101)

the magix number 101 is what date format it is converted to