Hibernate 一对一 关系的实现(外键)

实体类 Student 和 StudentInfo 是一对一的关系.可以采用共享主键或者外键约束的形式进行连接

 
构造实体类: 
 

public class Student {


 private int sid;


 private String name;


 private String password;


 private StudentInfo stdinfo; //这一条一定要加,下面省略了无参构造和getter setter  


} 
  

public class StudentInfo {

 private int sinfoid;


 private String email;


 private int qq;


 private String address;


 private int student_id; //新增加的外键字段


 private Student student;    //这一条一定要加,下面省略了无参构造和getter setter  


}

 
映射文件的写法:
student.hbm.xml: 没变
 

<hibernate-mapping package="day3.entity">
 <class name="day3.entity.Student" table="student1">
  <id column="id" name="sid">
   <generator class="native"/>
  </id>
  <property generated="never" lazy="false" name="name"/>
  <property generated="never" lazy="false" name="password"/>
  <one-to-one class="day3.entity.StudentInfo" name="stdinfo" cascade="all"/>
 </class>
</hibernate-mapping>
 

  
//=====================================================================
 

studentinfo.hbm.xml:
 
 <hibernate-mapping>
 <class name="day3.entity.StudentInfo" table="studentinfo">
  <id column="sinfoid" name="sinfoid">
  </id>
  <property generated="never" lazy="false" name="email"/>
  <property generated="never" lazy="false" name="qq"/>
  <property generated="never" lazy="false" name="address"/>
  <many-to-one class="day3.entity.Student" name="student" column="student_id"></many-to-one>   <!--此条很重要 用于设置外键-->
 </class>
</hibernate-mapping>