4 Entities and attributes

 

In this chapter

  • You start the design and analysis phase of database design.
  • You learn about keys and common data types in databases.
  • You design your first few entities, identifying their attributes, primary keys, and data types.
What you need to know

You can find the database design covered in this chapter (so far, only entities and attributes) implemented in tools commonly used by practitioners, such as dbdiagram.io and MySQL Workbench, in the GitHub repository (https://github.com/Neo-Hao/grokking-relational-database-design). You can navigate to the chapter_04 folder and follow the instructions in README.md to load the database design into corresponding tools.

The data types covered in this chapter apply to most relational database management systems (RDBMSs), such as MySQL, MariaDB, and PostgreSQL. If you use another RDBMS, such as SQL Server or SQLite, you need to make small modifications to the design by replacing certain data types with equivalents specific to the target RDBMS. You can find such information in README.md in the chapter_04 folder.

Overview

In chapter 3, you walked through the database design process and went over the requirements-gathering phase for the online store of The Sci-Fi Collective.

Entities and attributes

Keys

Data types

String data types: Power of personality

Integers: Number your way to success

Float like a butterfly, decimal like a data queen

Temporal data types: Time flies when you’re querying