Hibernate对象关系映射总结
@Entity@Table(name="t_jpa_Student1") public class Student1{ private int id; private String name; private Set<Teacher1> teachers= new HashSet<Teacher1>();@ManyToMany(mappedBy="students") public Set<Teacher1> getTeachers(){ return teachers;} public void setTeachers(Set<Teacher1> teachers){ this.teachers= teachers;}………………………………….}
@Entity@Table(name="t_jpa_teacher1") public class Teacher1{ private int id; private String name; private Set<Student1> students= new HashSet<Student1>();@ManyToMany@JoinTable(name="t_jpa_teacher_student", joinColumns={@JoinColumn(name="teacher_id")}, inverseJoinColumns={@JoinColumn(name="student_id" )} ) public Set<Student1> getStudents(){ return students;} public void setStudents(Set<Student1> students){ this.students= students;}………………………………….}
一对多单向关联：用户组用户
用户组知道自己有哪些用户：通过 groupid就能查询到用户
用户不知道自己所于哪个用户组