for example
CREATE TABLE user (
id INT(11) NOT NULL auto_increment PRIMARY KEY,
name VARCHAR(100) NOT NULL default ''
);
CREATE TABLE room (
id INT(11) NOT NULL auto_increment PRIMARY KEY,
address VARCHAR(100) NOT NULL default ''
);
User.hbm.xml
-
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="onlyfun.caterpillar.User" table="user">
<id name="id" column="id" type="java.lang.Integer">
<generator class="native"/>
</id>
<property name="name" column="name" type="java.lang.String"/>
<one-to-one name="room"
class="onlyfun.caterpillar.Room"
cascade="all"/>
</class>
</hibernate-mapping>
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="onlyfun.caterpillar.Room" table="room">
<id name="id" column="id">
<generator class="foreign">
<param name="property">user</param>
</generator>
</id>
<property name="address"
column="address"
type="java.lang.String"/>
<one-to-one name="user"
class="onlyfun.caterpillar.User"
constrained="true"/>
</class>
</hibernate-mapping>
java:
User user1 = new User();
user1.setName("bush");
Room room1 = new Room();
room1.setAddress("NTU-M8-419");
user1.setRoom(room1);
room1.setUser(user1);
Session session = sessionFactory.openSession();
Transaction tx = session.beginTransaction();
session.save(user1);
tx.commit();
session.close();
the above is run right,but if the following :
User user1 = new User();
user1.setName("bush");
Room room1 = new Room();
room1.setAddress("NTU-M8-419");
user1.setRoom(room1);
room1.setUser(user1);
User user2 = new User();
user2.setName("bush");
//the new column point to the same room1 and no errors
user2.setRoom(room1);
Session session = sessionFactory.openSession();
Transaction tx = session.beginTransaction();
session.save(user1);
//save
session.save(user2);
tx.commit();
session.close();
is "one-to-one" in hibernate just for creating a foreign key for another table?
did it make any restriction between the two tables.
posted on 2006-08-28 13:45
R.Zeus 阅读(212)
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