Hibernate @OneToMany Bidirectional Relationship

How to Program with Java Podcast

Since we’ve already learned about the unidirectional @ManyToOne relationship, we can now move on to talking about what a bidirectional relationship is like, when using Hibernate. The term “bidirectional” literally means “functioning in two directions”, which is the concept that we will apply in our relationships between two Java objects. When we have a bidirectional relationship between objects, it means that we are able to access Object A from Object B, and Object B from Object A. We can apply this logic to our real world coding example that we saw in the last post. The example we will use is the relationship between an Employer and an Employee. Previously, we only defined a unidirectional relationship, so we could only access the Employer from the Employee object and not vice-versa. Now let’s take a look at how to transform our existing unidirectional relationship into a bidirectional one.