A question that is frequently occurring among my SQL training‘s participants is:
What’s the difference between putting a predicate in the JOIN .. ON clause and the WHERE clause?
I can definitely see how that’s confusing some people, as there seems to be no difference at first sight, when running queries like these, e.g. in Oracle. I’m using the Sakila database, as always:
-- First query
SELECT a.actor_id, a.first_name,...