Hibernate 一对一 关系的实现(共享主键)

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 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:

 

<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"/>   <!-- 主要是注意这里-->

 </class>

</hibernate-mapping>

  

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

studentinfo.hbm.xml:

 

<hibernate-mapping>

 <class name="day3.entity.StudentInfo" table="studentinfo">

  <id column="sinfoid" name="sinfoid">

   <generator class="foreign">

     <param name="property">student</param>        <!--主要是这里啊,必须的-->

   </generator>

  </id>

  <property generated="never" lazy="false" name="email"/>

  <property generated="never" lazy="false" name="qq"/>

  <property generated="never" lazy="false" name="address"/>

  <one-to-one class="day3.entity.Student" name="student"></one-to-one>  <!--这里必不可少-->

 </class>

</hibernate-mapping>