符合条件的多个连接休眠

Question

我想用休眠连接4个表。我编写以下代码以获取课程名称，教师详细信息和课程表（按学生ID）： 我的学生实体是：

@Entity
@Table(name = "students", schema = "public")
public class Student {
    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "students_id_seq")
    @SequenceGenerator(name = "students_id_seq", sequenceName = "students_id_seq", allocationSize = 1)
    @Column(name = "id", nullable = false, unique = true)
    private int id;
    @Column(name = "name", nullable = false, length = 60)
    private String name;
    @Column(name = "code_melli", nullable = false, length = 10)
    private String codeMelli;
    @Column(name = "register_date", nullable = false)
    private Date registerDate;
    @Column(name = "mobile", length = 11)
    private String mobile;
    @Column(name = "phone", length = 15)
    private String phone;
    @Column(name = "email", length = 50)
    private String email;
    @JsonIgnore
    @OneToMany(fetch = FetchType.LAZY)
    @JoinColumn(name = "student_id", referencedColumnName = "id", insertable = false, updatable = false)
    private List<Attend> attends;

确定学生参加课程的我的参加实体，他的分数是：

@Entity
@Table(name = "attend", schema = "public")
public class Attend {

    @EmbeddedId
    AttendKey attendKey;

    @Column(name = "score")
    private int score;
    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "student_id", referencedColumnName = "id", insertable = false, updatable = false)
    private Student student;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "course_id", referencedColumnName = "id", insertable = false, updatable = false)
    private Course course;

映射课程详细信息的课程实体为：

@Entity
@Table(name = "courses", schema = "public")
public class Course {
    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "courses_id_seq")
    @SequenceGenerator(name = "courses_id_seq", sequenceName = "courses_id_seq", allocationSize = 1)
    @Column(name = "id", nullable = false, unique = true)
    private int id;
    @Column(name = "code")
    private int code;
    @Enumerated(EnumType.ORDINAL)
    @Column(name = "cluster", nullable = false)
    private ClusterType cluster;
    @Column(name = "name", nullable = false, length = 40)
    private String name;
    @OneToOne
    @JoinColumn(name = "teacher_id")
    private Teacher teacher;
    @Column(name = "students", nullable = false)
    private int students;
    @Column(name = "salary", nullable = false)
    private int salary;
    @Column(name = "tuition", nullable = false)
    private int tuition;
    @Column(name = "start_date")
    private Date startDate;
    @Column(name = "end_date")
    private Date endDate;
    @JsonIgnore
    @OneToMany(fetch = FetchType.LAZY)
    @JoinColumn(name = "course_id", referencedColumnName = "id", insertable = false, updatable = false)
    private List<Schedule> scheduleList;

在一周的某一天保存课程开始和结束时间的时间表实体是：

@Entity
@Table(name = "schedule", schema = "public")
@IdClass(ScheduleKey.class)
public class Schedule {

    @Id
    @Column(name = "course_id")
    private int course_id;
    @Id
    @Column(name = "day")
    @Enumerated(EnumType.ORDINAL)
    private Day day;

    @Column(name = "start", nullable = false)
    private Time start;
    @Column(name = "endt", nullable = false)
    private Time endt;

我该如何使用休眠标准API将这些表连接起来并获取特定学生的课程表。

用于获取数据的SQL查询：

select
    *
from
    students 
inner join
    attend  
        on students.id=attend.student_id 
inner join
    courses 
        on attend.course_id=course.id 
left outer join
    schedule_ 
        on course.id=schedule.course_id 
left outer join
    public.teachers 
        on course.teacher_id=teacher.id 
where
    students.id=102552

我使用

public Student getStudentDetail(int studentId) {
        Criteria criteria = createEntityCriteria();
        criteria.add(Restrictions.eq("id", studentId));
        criteria.setFetchMode("attends", FetchMode.JOIN);
        Criteria attendCriteria = criteria.createCriteria("attends", "attend")
                .setFetchMode("course", FetchMode.JOIN);
        Criteria courseCriteria = attendCriteria.createCriteria("course", "course")
                .setFetchMode("scheduleList", FetchMode.JOIN);
        Criteria scheduleCriteria = courseCriteria.createCriteria("scheduleList", "schedule");
        return (Student) scheduleCriteria.uniqueResult();
    }