1 Introduction to databases and SQL

 

In this chapter

  • You get a foundation for the rest of the book.
  • You learn the basics of relational databases.
  • You peek into database design.
  • You write your first SQL query and learn more about the basics of SQL.
What you need to know

As you read this chapter, you will find some code snippets. If you want to execute those code snippets covered in this chapter, you will need to load some prepared scripts into a database system. You can find the target scripts in the chapter_01 folder in our GitHub repository (https://github.com/Neo-Hao/grokking-relational-database-design), and follow the instructions in the README.md file to run the scripts.

1.1 Overview

Database design is a critical yet easily neglected step in software development. Nearly every application requires data storage and management to some extent, but not every application has a well-designed database. If you design a database without knowing the principles of effective database design, your application may suffer from a series of issues you weren’t expecting, such as disorganized data or queries taking too long and too many resources to run. Such issues can lead to bugs and a bad user experience.

1.2 Relational databases

1.2.1 Tables, entities, and primary keys

1.2.2 Relational database management systems and Structured Query Language

1.3 Your first SQL query

1.4 The basics of SQL queries

1.4.1 Filtering

1.4.2 Aggregation

1.4.3 Table and data management

1.5 Summary