13. Video: Motivation for Other JOINs

Expert Tip

You have had a bit of an introduction to these one-to-one and one-to-many relationships when we introduced PKs and FKs. Notice, traditional databases do not allow for many-to-many relationships, as these break the schema down pretty quickly. A very good answer is provided here.

The types of relationships that exist in a database matter less to analysts, but you do need to understand why you would perform different types of JOINs, and what data you are pulling from the database. These ideas will be expanded upon in the next concepts.