Tests for preparation:

Database Basics https://www.classtime.com/code/MWG8KQ

Normalization https://www.classtime.com/code/QVJ4RP

SQL. DDL https://www.classtime.com/code/YNJ9Q9

SQL. DML https://www.classtime.com/code/5VN35Z

SQL https://www.classtime.com/code/GNGQ43