SQLite query to join on a range of dates?

Question

I am working with SQLite.

Suppose I have a table sales with two columns, date and count, to keep track of how many glasses of lemo

Answer 1

I think you need something like this:

SELECT sum(count) / ((strftime('%s','2010-01-10')-strftime('%s','2010-01-04')+86400)/86400)
FROM sales
WHERE date IS BETWEEN '2010-01-04' AND '2010-01-10';

The query calculates the exact number of days by taking the seconds between the given dates
and dividing with 86400 (= 24*3600) secs.

For example

SELECT (strftime('%s','2010-03-01')-strftime('%s','2010-01-01') + 86400) / 86400

outputs 60 which is the correct value.

Check out SQLite's Date And Time Functions.