How to map entities B on entities A using a Varchar column on table B?

Question

I have some difficulties with a JPA scenario that i'm unable to resolve. I search on Stackoverflow a similar case, but i didn't found.

I only found this topic, but it's not exactly my case...

If it already exists, I'm sorry.

Here's my case :

I have two tables :

A :

id	label	ref_name
1	ARK	Bruce
2	HAM	Alfred

B :

id	name	lastname
1	Bruce	Wayne
2	Alfred	Pennyworth
3	Bruce	Banner

Table B represents a list of persons. Table A has a label name, and a column to list all persons from Table B that has a particular name.

In Java I have these 2 entities :

public class B {

   private Integer id;

   private String name;

   private String lastname;
}

public class A {

   private Integer id;

   private String label;

   @ManyToMany
   @JoinColumn(name="ref_name", referencedColumnName="name")
   private List<B> persons;
}

So, I've tried this code, and i have the following error message :

ERROR: relation "A_persons" does not exist

I can't figure what's wrong with this ...

Thank you for your help !

Answer 1

By observing your use of many-to-many mapping, I am guessing you are trying to do many-to-many mapping without the use of a "junction-table". I found this Stackoverflow answer showing how this can be done. What do you think? https://stackoverflow.com/a/25018992

public class A {
    private Integer id;
    private String label;
    @OneToMany
    @JoinColumn(name="ref_name",
        referencedColumnName="name")
    private List<B> persons;
}