Question

I have the following table structure:

ID, User_ID, DateTime

Which stores a user id and datetime of an order purchased. How would I get the average number of orders a day, across every row?

In pseudo code I’m thinking:

1. Get total number of orders
2. Get number of days in range (from first row to last row).
3. Divide 1. by 2. to get average?

So it would return me a value of 50, or 100?

Thanks

Answer 1

Since you know the date range, and you are not guaranteed to have and order on these dates, you can’t just subtract the max(date) from min(date), but you know the number of days before you run the query, therefore simply:

select count(*) / <days>
from mytable
where DateTime between <start> and <end>

Where you supply the indicated values because you know them.