It took me quite some time before I could reason efficiently about SQL JOINs. And I must admit, the set theory diagrams never helped me really understand JOINs in SQL. So today, I want to help you understand JOINs in a different way, hoping to make the concept click at once for you too!
As we saw in the previous article What is an SQL relation?, in SQL a relation is a collection of objects, all sharing the same definition.