使用自连接访问两个别名记录的JPA

@Entity
@Table(name = "employees")
public class Employee {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    
    private String name;
    
    @ManyToOne
    @JoinColumn(name = "manager_id")
    private Employee manager;
    
    // getters and setters
}

// 使用自连接查询员工及其上级领导
public List<Employee> getEmployeesAndManagers() {
    EntityManager entityManager = // 获取EntityManager对象
    
    String jpql = "SELECT e1, e2 FROM Employee e1, Employee e2 WHERE e1.manager = e2";
    TypedQuery<Object[]> query = entityManager.createQuery(jpql, Object[].class);
    List<Object[]> results = query.getResultList();
    
    List<Employee> employees = new ArrayList<>();
    for (Object[] result : results) {
        Employee employee = (Employee) result[0];
        Employee manager = (Employee) result[1];
        employee.setManager(manager);
        employees.add(employee);
    }
    
    return employees;
}