Hibernate多対多注釈チュートリアル

CREATE TABLE `employee` (
  `employee__id` int(11) NOT NULL AUTO__INCREMENT,
  `first__name` varchar(50) DEFAULT NULL,
  `last__name` varchar(50) DEFAULT NULL,
  PRIMARY KEY (`employee__id`)
) ENGINE=InnoDB AUTO__INCREMENT=17 DEFAULT CHARSET=utf8;

CREATE TABLE `project` (
  `project__id` int(11) NOT NULL AUTO__INCREMENT,
  `title` varchar(50) DEFAULT NULL,
  PRIMARY KEY (`project__id`)
) ENGINE=InnoDB AUTO__INCREMENT=18 DEFAULT CHARSET=utf8;

CREATE TABLE `employee__project` (
  `employee__id` int(11) NOT NULL,
  `project__id` int(11) NOT NULL,
  PRIMARY KEY (`employee__id`,`project__id`),
  KEY `project__id` (`project__id`),
  CONSTRAINT `employee__project__ibfk__1`
   FOREIGN KEY (`employee__id`) REFERENCES `employee` (`employee__id`),
  CONSTRAINT `employee__project__ibfk__2`
   FOREIGN KEY (`project__id`) REFERENCES `project` (`project__id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

@Entity
@Table(name = "Employee")
public class Employee {
   //...

    @ManyToMany(cascade = { CascadeType.ALL })
    @JoinTable(
        name = "Employee__Project",
        joinColumns = { @JoinColumn(name = "employee__id") },
        inverseJoinColumns = { @JoinColumn(name = "project__id") }
    )
    Set<Project> projects = new HashSet<>();

   //standard constructor/getters/setters
}

@Entity
@Table(name = "Project")
public class Project {
   //...

    @ManyToMany(mappedBy = "projects")
    private Set<Employee> employees = new HashSet<>();

   //standard constructors/getters/setters
}

public class HibernateManyToManyAnnotationMainIntegrationTest {
    private static SessionFactory sessionFactory;
    private Session session;

   //...

    @Test
    public void givenData__whenInsert__thenCreatesMtoMrelationship() {
        String[]employeeData = { "Peter Oven", "Allan Norman" };
        String[]projectData = { "IT Project", "Networking Project" };
        Set<Project> projects = new HashSet<>();

        for (String proj : projectData) {
            projects.add(new Project(proj));
        }

        for (String emp : employeeData) {
            Employee employee = new Employee(emp.split(" ")[0],
              emp.split(" ")[1]);

            assertEquals(0, employee.getProjects().size());
            employee.setProjects(projects);
            session.persist(employee);

            assertNotNull(employee);
        }
    }

    @Test
    public void givenSession__whenRead__thenReturnsMtoMdata() {
        @SuppressWarnings("unchecked")
        List<Employee> employeeList = session.createQuery("FROM Employee")
          .list();

        assertNotNull(employeeList);

        for(Employee employee : employeeList) {
            assertNotNull(employee.getProjects());
        }
    }

   //...
}