Intro to Spring Boot: Persisting One-to-Many Relationships

Notes

In this lesson we'll look at how to structure model objects that have relationships with each other. In particular, we'll look at one-to-many relationships. "One-to-many relationships" describe classes that can have many instances of another class.

In our cheese-mvc application, an example of this is the relationship between the Cheese class and the Category class. Each Category may have many Cheese objects related to it. Therefore, we use the @OneToMany annotation within the Category class, along with the @JoinColumn annotation, above our declaration of the cheeses ArrayList. Then, in our Cheese class, we use the @ManyToOne annotation above the declaration of the category field.

For a more detailed walkthrough of the code in this video, look at Parts 1-3 of the CheeseMVC Persistent studio.

Code

We start this lesson with the code in the video-one2many-start branch of the cheese-mvc repo: starting code

You'll create the code for the end of the lesson yourself as part of an in-class studio!