How to define JPA Repository Query with a Join?

Question

I would like to make a Join query by Jpa repository by annotation @Query I have three tables.

The native query is:

select application.APP_ID 
from user, customer, application 
where user.USE_CUSTOMER_ID = customer.CUS_ID 
and application.APP_CUSTOMER_ID = customer.CUS_ID 
and user.USE_ID=1;

Now I have Table Hibernate entity, so I tried in ApplicationRepository

@Query(SELECT  application FROM  Application a
  INNER JOIN customer c ON c.customer.id = a.customer.id 
  INNER JOIN user u ON u.customer.id = c.customer.id
  INNER JOIN application a ON a.user.id = u.id
  WHERE
  u.id = :user.id)
List<Application> findApplicationsByUser(@Param("User") User user);

The log says

unexpected token

Any ideas, please?

My table Entity

Application.java:

@Entity
@Table
public class Application extends BaseSimpleEntity {
...
    @ManyToOne(optional = false)
    private Customer customer;
...
}

Customer.java:

@Entity
@Table
public class Customer extends BaseSimpleEntity {
...
    @OneToMany(mappedBy = "customer")
    private List<User> users;
    @OneToMany(mappedBy = "customer")
    private List<Application> applications;
...
}

User.java:

@Entity
@Table
public class User extends BaseSimpleEntity {
...
    @ManyToOne(optional = false)
    private Customer customer;
...
}

Answer 1

You don't need ON clauses in JPA, because the JPA already know how entities are associated thanks to the mapping annotations.

Moreover, you're selecting application , which is not an alias defined in your query.

And your joins make no sense.

The query should simply be

select application FROM Application a
join a.customer c 
join c.users u
where u.id = :userId

Read the Hibernate documentation to understand how HQL and joins work.