I have a question since I'm new to SQL:
I have a table which contains 3 columns: a customer_id, type_of_event which is check-in or check-out, and date.
so each customer_id has exactly 2 rows of check in and check out.
I need to calculate the general AVERAGE amount of days of stay (average of all stays in term of days)
I hope I'm clear enough. Would appreciate some help.
Thanks a lot!