Hibernate ManyToOne vs OneToOne
They look exactly the same on schema but there is difference on Hibernate Layer. If you try something like that: Address address = new Address(); Order order1 = new Order(); order1.setAddress(address); Order order2 = new Order(); order2.setAddress(address); save(); Everything will be OK. But, after save if you try get Order: @OneToOne case: org.hibernate.HibernateException: More than …