I have a simple Department Entity with one attribute name which I set to be unique.
@Entity
@XmlRootElement
public class Department {
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Id
@Column(name = "id")
private int id;
@Basic
@Column(name = "name", unique = true)
private String name;
@ManyToMany(mappedBy = "departments")
@JsonbTransient
@XmlTransient
private Set<Employee> employees = new HashSet<Employee>();
...
methods
}
And the following code to insert a new Department entry in my DB.
...
transaction.begin();
entityManager.createNativeQuery("insert into mydb.department (department.name)" +
"values (:deptName)", Department.class)
.setParameter("deptName", department.getName())
.executeUpdate();
transaction.commit();
...
Now after I run a few tests on Postman, I realized that even after trying to insert a duplicate Department and get the "message":"org.hibernate.exception.ConstraintViolationException: could not execute statement" exception, the ID of the next entry will be increased.
I don't understand, what (MySQL, jdbc, javax.persistence, Hibernate) causes this?
Is this a normal behavior, or is there a way to fix this?
