If you feel like diving deeper into the world of relational databases and SQL, here is a book that you might wanna consider getting. Please note that purchasing this book is only recommended and completely optional. This book is not a required part of our data science curriculum here.
Introduction to SQL: Mastering the Relational Database Language 4th Edition
SQL was, is and always will be the database language for relational database systems such as Oracle, DB2, MySQL, and Microsoft SQL Server. Introduction to SQL describes in depth the full capacity of SQL as it is implemented by all the major commercial databases, without neglecting the most recent changes to the standard. Unique in the extent of its coverage, this book takes you from the beginning to the end of SQL, the concepts to the practice, the apprentice to the master. You don’t just learn how to do something, but you learn why SQL works the way it does. Van der Lans illustrates each aspect of SQL with many practical examples, and provides exercises in each chapter to make sure you have grasped the concepts. Previous editions have been well received, and have sold well. This edition brings it up to date for the most recent SQL standard, as well as with the most recent versions of Microsoft SQL Server, Oracle, DB2, and MySQL. The author is an insider on the SQL standard committee.