可以使用实体字段保留JPA实体吗？

Question

If I have an entity such as the following:

@Entity
public class Customer {
    private Address address;
}

And the Address is also an entity:

@Entity
public class Address {...}

Does persisting the Customer in turn persist its contained Address? Or is this not possible at all? The idea was basically to have a main entity that consists of its fields, some of which are entities themselves that will be stored in individual tables. Some of the fields of Customer are unique in that I also would like a Customer table for that data. Unless I'm just missing it, I haven't been able to find this answer. This was something I was just curious about and I'm not currently on a machine where I can try it, so I wanted to ask first.

Thanks in advance.

Answer 1

This is possible and JPA basics. But you have to define the associations between entities in your entity classes.

I recommend reading a good tutorial on this topic, eg the Java EE6 tutorial .

Answer 2

You have 2 options depending on your domain model:

• removing the @Entity from address and annotate it with @Embeddable

• mapping the Address in the Person with: @OneToOne(cascade = {CascadeType.PERSIST})