hibernate笔记（三）------many2many

create table e_order ( orderid integer not null auto_increment, name varchar(255), cost double precision, paywayid integer, userid integer, statusid integer, primary key (orderid) ) create table e_orderLine ( orderlineid integer not null auto_increment, orderid integer, amount integer, productid integer, primary key (orderlineid) ) 联合主键 create table e_order_orderline ( orderid integer not null, orderlineid integer not null, primary key (orderlineid, orderid) ) hibernate多对多关联映射(单向Order---->OrderLine)

 

多对多单向跟一对多单向很相似。只是中间插入了一个表别对应两边表的id值

 

<class name="Order" table="e_order"> <id name="orderid"> <generator class="native" /> </id> <property name="name" /> <property name="cost" /> <set name="orders" table="e_order_orderline" order-by="orderlineid"> <key column="orderid"/> <many-to-many class="OrderLine" column="orderlineid"></many-to-many> </set> <many-to-one name="payway" column="paywayid"/> <many-to-one name="user" column="userid"/> <many-to-one name="status" column="statusid"/> </class>

 

 

hibernate多对多关联映射(单向Order<---->OrderLine)

table属性值必须和单向关联中的table属性值一致
<key>中column属性值要与单向关联中的<many-to-many>标签中的column属性值一致
在<many-to-many>中的column属性值要与单向关联中<key>标签的column属性值一致

 

 

这就需要在OrderLine中再加入一个set  对应  Orders

 

<class name="OrderLine" table="e_orderLine"> <id name="orderlineid"> <generator class="native" /> </id> <property name="orderid" /> <property name="amount" /> <set name="orders" table="e_order_orderline"> <key column="orderlineid"/> <many-to-many class="OrderLine" column="orderid"/> </set> <many-to-one name="product" column="productid"/> </class>