@OneToMany with @JoinTable error

Question

I am trying to understand **@OneToMany** with **@JoinTable** for such a scenerio

I am using JPA 2.1, Hibernate 5.0.4 and Oracle 11 XE. When I call userDao.save(user) (code below), I have

 java.sql.SQLIntegrityConstraintViolationException: ORA-00001: unique constraint (HIBERNATE.USER2ORDER_PK) violated 

What am I doing wrong? Can someone help me understand?

DDL:

 DROP TABLE HIBERNATE.T_USER2ORDERS; DROP TABLE HIBERNATE.T_ORDERS; DROP TABLE HIBERNATE.T_USERS; DROP SEQUENCE HIBERNATE.USERS_SEQ; DROP SEQUENCE HIBERNATE.ORDERS_SEQ; CREATE TABLE HIBERNATE.T_USERS ( ID NUMBER(15), NAME VARCHAR2(100 CHAR), CONSTRAINT USER_PK PRIMARY KEY (ID) ); CREATE TABLE HIBERNATE.T_ORDERS ( ID NUMBER(15), ORDER_DETAILS VARCHAR2(100 CHAR) NOT NULL, CONSTRAINT UDETAILS_PK PRIMARY KEY (ID) ); CREATE TABLE HIBERNATE.T_USER2ORDERS ( ID_USER NUMBER(15) NOT NULL, ID_ORDER NUMBER(15) NOT NULL, CONSTRAINT USER2ORDER_PK PRIMARY KEY (ID_USER), CONSTRAINT USER_FK FOREIGN KEY (ID_USER) REFERENCES T_USERS(ID), CONSTRAINT ORDER_FK FOREIGN KEY (ID_ORDER) REFERENCES T_ORDERS(ID) ); CREATE SEQUENCE HIBERNATE.USERS_SEQ START WITH 1 INCREMENT BY 1 NOCACHE NOCYCLE; CREATE SEQUENCE HIBERNATE.ORDERS_SEQ START WITH 1 INCREMENT BY 1 NOCACHE NOCYCLE; 

Dao:

 @Repository @Transactional public class UserDaoImpl extends HibernateDaoSupport implements UserDao { public static final Logger LOG = LoggerFactory.getLogger(UserDaoImpl.class); @Autowired public UserDaoImpl(SessionFactory sessionFactory) { setSessionFactory(sessionFactory); } @Override public Serializable save(UserModel user) { return getHibernateTemplate().save(user); } } 

UserModel:

 @Entity @Table(name = "T_USERS") @SequenceGenerator(name = "users-sequence-generator", sequenceName = "USERS_SEQ", initialValue = 0, allocationSize = 1) public class UserModel { @Id @Column(name = "id") @GeneratedValue(generator = "users-sequence-generator", strategy = GenerationType.SEQUENCE) private Long id; @Column(name = "name") private String name; @OneToMany( cascade = CascadeType.ALL, orphanRemoval = true, fetch = FetchType.EAGER) @JoinTable( name="t_user2orders", joinColumns = {@JoinColumn(name="id_user", referencedColumnName="id")}, inverseJoinColumns = {@JoinColumn(name="id_order", referencedColumnName="id")} ) private Collection<OrderModel> orders = new LinkedHashSet<>(); public Long getId() { return id; } public void setId(Long id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Collection<OrderModel> getOrders() { return orders; } public void setOrders(Collection<OrderModel> orders) { this.orders = orders; } } 

OrderModel:

 @Entity @Table(name="T_ORDERS") @SequenceGenerator(name="orders-sequence-generator", sequenceName="ORDERS_SEQ", initialValue=0, allocationSize=1) public class OrderModel { @Id @Column(name="id") @GeneratedValue(generator="orders-sequence-generator", strategy=GenerationType.SEQUENCE) private Long id; @Column(name="order_details") private String orderDetails; public Long getId() { return id; } public void setId(Long id) { this.id = id; } public String getOrderDetails() { return orderDetails; } public void setOrderDetails(String orderDetails) { this.orderDetails = orderDetails; } } 

Answer 1

Thanks to @tharindu_DG suggestions, I found an error.

The only restriction on T_USER2ORDERS is not valid.

Instead of CONSTRAINT USER2ORDER_PK PRIMARY KEY (ID_USER) should be CONSTRAINT USER2ORDER_PK PRIMARY KEY (ID_ORDER)

Thanks for the help.

Answer 2

A unique limitation when joining the USERS2ORDERS table is to have a primary key as a combination of both user_id and order_id. However, it is recommended to have a primary key as record_id, you do not know when you can use it.