Introducing relational databases

A database is a critical component in data-driven businesses and organizations, and data scientists need to understand its structure, functions, and underlying language. This section aims to introduce you to relational databases, focusing on the common language of SQL.

A relational database (also known as a SQL database) is a type of database that organizes data into tables, where each table has rows and columns. Each table represents a specific entity type, such as Customers or Products. Much like DataFrames, each row represents a unique record (or records), and each column represents a field (or attribute) of the data. This relational model introduced a standard way to represent and query data independent of any specific application. You can see an example of a relational database in Figure 5.1:

Figure 5.1: Relational data model example – star schema

What makes relational databases so powerful is their ability...