[Java教程]多对多的单向关联
0 2017-04-21 12:00:34
一个老师(Teacher)教多个学生(Student)，一个学生(Student)可以有多名老师(Teacher)，这就是一对一的关系，下面以这个例子为例进行配置：
Annotataion 配置：
Teacher:
1 package com.bjsxt.hibernate; 2 3 import java.util.HashSet; 4 import java.util.Set; 5 6 import javax.persistence.Entity; 7 import javax.persistence.GeneratedValue; 8 import javax.persistence.Id; 9 import javax.persistence.JoinColumn;10 import javax.persistence.JoinTable;11 import javax.persistence.ManyToMany;12 import javax.persistence.Table;13 14 @Entity15 @Table(name="t_teacher")16 public class Teacher {17 18 private Integer id;19 20 private String name;21 22 private Set students = new HashSet();23 24 @Id25 @GeneratedValue26 public Integer getId() {27 return id;28 }29 30 public void setId(Integer id) {31 this.id = id;32 }33 34 public String getName() {35 return name;36 }37 38 public void setName(String name) {39 this.name = name;40 }41 42 @ManyToMany43 @JoinTable(name="t_s",44 joinColumns={@JoinColumn(name="teacher_id")},45 inverseJoinColumns={@JoinColumn(name="student_id")}46 )47 public Set getStudents() {48 return students;49 }50 51 public void setStudents(Set students) {52 this.students = students;53 }54 55 }
Student:1 package com.bjsxt.hibernate; 2 3 import javax.persistence.Entity; 4 import javax.persistence.GeneratedValue; 5 import javax.persistence.Id; 6 import javax.persistence.Table; 7 8 @Entity 9 @Table(name="t_student")10 public class Student {11 private Integer id;12 13 private String name;14 15 @Id16 @GeneratedValue17 public Integer getId() {18 return id;19 }20 21 public void setId(Integer id) {22 this.id = id;23 }24 25 public String getName() {26 return name;27 }28 29 public void setName(String name) {30 this.name = name;31 }32 }
Teacher.hbm.<?mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
Student.hbm.1 2 "-//Hibernate/Hibernate Mapping DTD 3.0//EN" 4 "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> 5 6 7 8 9 10 11 12 13
上面两种方式，生成SQL的结果一样，生成顺序：
jar链接: https://pan.baidu.com/s/1eSKKZ8Q 密码: puad
代码链接: https://pan.baidu.com/s/1bpxk8H5 密码: e7ku
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