我有两个实体部门和雇员。部门有一个雇员列表。雇员有一个部门字段。我可以创建雇员并将他们添加到部门内的列表中。数据库表按预期填充。如果我查询部门，我会得到部门，雇员列表也会填充。这样一切都很好。如果我查询雇员，并得到部门字段，它会返回null。

@Entity
@Table(name = "DEPARTMENT")
public class Department {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "DPT_ID")
    private long id;

    @Column(name = "NAME", nullable = false, unique = true)
    private String name;

    @OneToMany(cascade = CascadeType.ALL)
    @JoinColumn(name = "DEPARTMENT") //we need to duplicate the physical information
    private List<Employee> employees = new ArrayList<>();
…

--

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

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "EMP_ID")
    private long id;

    @Column(name = "NAME", nullable = false)
    private String name;

    @Column(name = "DESIGNATION")
    private String designation;

    @ManyToOne
    @JoinColumn(name = "DEPARTMENT", insertable = false, updatable = false)
    private Department department;
...

--
employee.getDepartment（）返回空值的查询

session = HibernateUtil.getSessionFactory().openSession();
        transaction = session.getTransaction();
        transaction.begin();

        Department department = new Department();
        department.setName("IT Department");

        Employee employee1 = new Employee();
        employee1.setName("Adam");
        employee1.setDesignation("Manager");

        Employee employee2 = new Employee();
        employee2.setName("Miller");
        employee2.setDesignation("Software Engineer");

        Employee employee3 = new Employee();
        employee3.setName("Smith");
        employee3.setDesignation("Associate  Engineer");

        department.getEmployees().add(employee1);
        department.getEmployees().add(employee2);
        department.getEmployees().add(employee3);

        session.persist(department);
        session.flush();
        transaction.commit();

        transaction = session.getTransaction();
        transaction.begin();

        {
            CriteriaBuilder builder = session.getCriteriaBuilder();
            CriteriaQuery<Employee> query = builder.createQuery(Employee.class);
            Root<Employee> root = query.from(Employee.class);
            query.select(root);
            Query<Employee> q = session.createQuery(query);
            List<Employee> employees = q.getResultList();
            for (Employee employee : employees) {
                System.out.println("EMPLOYEE NAME: " + employee.getName());
                System.out.println("DEPARTMENT NAME: " + employee.getDepartment()); // gives null
            }
        }
        {
            CriteriaBuilder builder = session.getCriteriaBuilder();
            CriteriaQuery<Department> query = builder.createQuery(Department.class);
            Root<Department> root = query.from(Department.class);
            query.select(root);
            Query<Department> q = session.createQuery(query);
            List<Department> departments = q.getResultList();
            for (Department deps : departments) {
                System.out.println(deps.getName());
                System.out.println(deps.getEmployees()); // list of employees is filled
            }
        }

第一节第一节第一节第一节第一次
这些表看起来填充正确，但是如果我对查询的Employee使用getDepartment，得到的是null，如果我对查询的Department使用getEmployees，得到的是所有Employees。
I tried both ways described here : https://docs.jboss.org/hibernate/orm/4.1/manual/en-US/html/ch07.html#collections-bidirectional
例7.21双向一对多，多对一方作为关联所有者
以及
例7.22一对多方作为所有者的双向关联
我也一样。
我错过了什么？
以下是完整的测试项目：updated Project zip
解决的固定项目：SOLVED PROBLEM PROJECT