JPA expecting ID column on joined table - jpa

Question

I'm attempting to represent a join table with JPA, however the generated SQL is expecting an id field on one of the tables.
The generated SQL is very close, but appears an ID column is expected on Permission table and used as the FK on the join table, which I was hoping not to do. See schema below:
You can see I am not using an ID column on permission table, instead letting the text representation of the permission be the key.
User.java
#Entity
#Data
#Table(name = "user")
public class User {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private int id;
private int accountId;
private String name;
private String email;
private String password;
private boolean admin;
#ManyToMany
#JoinTable(
name = "user_permission",
joinColumns = #JoinColumn(name = "id"),
inverseJoinColumns = #JoinColumn(name = "permission"))
private List<Permission> permissions;
}
Permission.java
#Data
#Entity
public class Permission {
#Id
private String permission;
private String permissionName;
private String permissionDescription;
}
Generated SQL
select
permission0_.id as id1_2_0_,
permission0_.permission as permissi2_2_0_,
permission1_.permission as permissi1_0_1_,
permission1_.permission_description as permissi2_0_1_,
permission1_.permission_name as permissi3_0_1_
from user_permission permission0_
inner join permission permission1_ on permission0_.permission=permission1_.permission
where permission0_.id=?
Error
ERROR 15056 --- [tp1962586186-25] o.h.engine.jdbc.spi.SqlExceptionHelper : Unknown column 'permission0_.id' in 'field list'

Answer 1

The problem was join columns name. It should have been mapped to the mapping tables FK instead of the parent tables PK. Above example is fixed with this change
#ManyToMany
#JoinTable(
name = "user_permission",
joinColumns = #JoinColumn(name = "user_id"),
inverseJoinColumns = #JoinColumn(name = "permission"))
private List<Permission> permissions;