4 lessons
What is a database, really?
Why we don't just save everything in a text file, and the one idea every database in the world is built on.
The relational model - tables, rows and columns
Why almost every serious database organizes data into tables, and the set theory quietly sitting underneath them.
Data types and NULL: what a column is allowed to hold
Why databases force every column to have a fixed type, and the surprisingly tricky logic of "missing" data.
Setting up your first database
Installing a real database on your machine, connecting to it, and running your very first commands - the practical, hands-on lesson.