Answer: Certainly! Here's a query that retrieves the patron ID and the average number of days patrons keep books during a checkout. It limits the results to only patrons with at least three checkouts and sorts the results in descending order by the average days the book is kept, and then in ascending order by patron ID:
SELECT patron_id, AVG(DATEDIFF(return_date, checkout_date)) AS average_days
FROM checkouts
GROUP BY patron_id
HAVING COUNT(*) >= 3
ORDER BY average_days DESC, patron_id ASC;
In this query, I assume there's a table named checkouts that contains the checkout information with columns patron_id, checkout_date, and return_date. The DATEDIFF function calculates the difference in days between the return_date and checkout_date. We group the results by patron_id and use the HAVING clause to filter only those patrons who have at least three checkouts. Finally, we sort the results in descending order by the average days and then in ascending order by patron ID.
Please make sure to replace checkouts with the actual name of your table containing the checkout data, and adjust the column names accordingly if they differ in your schema.
Step-by-step explanation: