@JoinTable联接三个表

Question

How can I use @JoinTable to join three tables?

I have three tables:

user:
id, name 

post:
id, date

company:
id, name

I want to create a new table with the following columns:

user_id, post_id, company_id.

I used:

@JoinTable(name = "new_table", joinColumns = @JoinColumn(name = "user_id"),
    inverseJoinColumns = @JoinColumn(name = "post_id"))

However, I am not sure how to add the third column.

Answer 1

You must not will use @JoinTable annotation. The @JoinTable annotation is used only to @ManyToMany relationship.

You need create a new Entity with three field, and each field must has the @ManyToOne and @JoinColumn annotation.

For Instance:

@Entity
@Table(name = "table_name")
class NewEntity {

    //Id and anothers fields

    @ManyToOne
    @JoinColumn(name = "user_id")
    private User user;

    @ManyToOne
    @JoinColumn(name = "post_id")
    private Post post;

    @ManyToOne
    @JoinColumn(name = "company_id")
    private Company company;

    //getters and setters       
}