In this chapter, we will cover the following recipes:
One-to-one mapping using a foreign key association
One-to-one mapping using a common join table
One-to-one mapping using a common primary key
One-to-many mapping or many-to-one mapping
Many-to-many mapping
Introduction
An association represents the relationship between tables. There are two main types of associations: unidirectional and bidirectional. We will take a look at how to use associations with an example.
There are four main well-known types of relationships:
One-to-one
One-to-many
Many-to-one
Many-to-many
There are multiple ways to achieve these relationships.