4 Database design

 

This chapter covers

  • Design mistakes in SQL Server and why it is important to avoid them
  • The mistake of failing to normalize your database
  • Mistakes made when designing and creating keys

In this chapter, we will discuss common mistakes that are made when designing databases. These mistakes can cause multiple challenges, leading to issues such as poorly performing code.

Design mistakes are introduced at the earliest stage of the development lifecycle before any code has been written. To illustrate this, let’s focus on MagicChoc. The company feels that its processes are too fragmented, so it has commissioned a new application, which will combine its non-internet sales and procurement functions into a single interface with a single backend. For this purpose, the MagicChoc management team has stated that they want to store the following data items:

4.1 #11 Failing to normalize

4.1.1 Designing a schema using judgment

4.1.2 Problems with our database schema

4.1.3 Designing a database schema using normalization

4.2 #12 Using a wide primary key

4.3 #13 Not using foreign keys

Summary