Hibernate之关联映射

单向，双向。
Student Address
一、单向多对一：
<hibernate-mapping package="com.lubby.pojo">
<class name="Student" table="t_students">
<id name="sid" >
<generator class="native"></generator>
</id>
<property name="sname"></property>
<many-to-one name="address" class="Address" cascade="save-update" ></many-to-one>
</class>
二、单向一对一：
    在many-to-many一方加上unique="true"就行了
<hibernate-mapping package="com.lubby.pojo">
<class name="Student" table="t_students">
<id name="sid" >
<generator class="native"></generator>
</id>
<property name="sname"></property>
<many-to-one name="address" class="Address" cascade="save-update" unique="true"></many-to-one>
</class>
</hibernate-mapping>


三、基于主键的单向一对一：
<hibernate-mapping package="com.lubby.pojo">
<class name="Student" table="t_students">
<id name="sid" >
<generator class="foreign">
<param name="property">address</param>
</generator>
</id>
<property name="sname"></property>
<one-to-one name="address" ></one-to-one>
</class>
</hibernate-mapping>
四、单向一对多


<hibernate-mapping package="com.lubby.pojo">
<class name="Student" table="t_students">
<id name="sid" >
<generator class="native" />
</id>
<property name="sname"></property>
<set name="address">
<key column="addid"></key>
<one-to-many class="Address"/>
</set>
</class>
</hibernate-mapping>




五、双向一对多 就是一的一方可以访问到多的一方，多的一方也可以访问到一的一方
<hibernate-mapping package="com.lubby.pojo">
<class name="Student" table="t_students">
<id name="sid" >
<generator class="native" />
</id>
<property name="sname"></property>  
//inverse是将关系交给多的一方维护
<set name="address" cascade="save-update" inverse="true">
//这里是对方表的外键列
<key column="stuid"></key>
<one-to-many class="Address"  />
</set>
</class>
</hibernate-mapping>


<hibernate-mapping package="com.lubby.pojo">
<class name="Address" table="t_address">
<id name="aid" >
<generator class="native"></generator>
</id>
<property name="city"></property>
<property name="street"></property>
//这里的column必须与对方配置的key相同
<many-to-one name="student" class="Student" column="stuid" not-null="true" cascade="save-update"></many-to-one>
</class>
</hibernate-mapping>




六、双向多对多


<hibernate-mapping package="com.lubby.pojo">
<class name="Address" table="t_address">
<id name="aid" >
<generator class="native"></generator>
</id>
<property name="city"></property>
<property name="street"></property>
<set name="student" table="t_stu_add" >
//这里是连接表的主键名称
<key column="addid"></key>
//这里是对应的类和连接表上的属性，
//要注意的是两个多对多类的配置文件中的key 为对方的column
<many-to-many class="Student" column="stuid"></many-to-many>
</set>
</class>
</hibernate-mapping>


<hibernate-mapping package="com.lubby.pojo">
<class name="Student" table="t_students">
<id name="sid" >
<generator class="native" />
</id>
<property name="sname"></property>
<set name="address" table="t_stu_add" cascade="save-update">
<key column="stuid"></key>
<many-to-many class="Address" column="addid"></many-to-many>
</set>
</class>
</hibernate-mapping>


了解和熟练掌握Java  、 Jsp 、 Servlet 、Struts 、Hibernate 、Spring等对网络协议了解和熟练掌握-->RIP RIPV2 EIGRP OSPF BGP MPLS VPN 对网络安全略有涉及 如VPN  ARP攻击 密码学、PKI 3A 等