實體:
package bi.one2many; import java.util.HashSet; import java.util.Set; public class Emperor { private int id; private String name; private Set<Minister> ministers = new HashSet<Minister>(); public Emperor() { } public Emperor(int id, String name, Set<Minister> ministers) { super(); this.id = id; this.name = name; this.ministers = ministers; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Set<Minister> getMinisters() { return ministers; } public void setMinisters(Set<Minister> ministers) { this.ministers = ministers; } } package bi.one2many; public class Minister { private int id; private String name; private Emperor emperor; public Minister() { } public Minister(int id, String name, Emperor emperor) { super(); this.id = id; this.name = name; this.emperor = emperor; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Emperor getEmperor() { return emperor; } public void setEmperor(Emperor emperor) { this.emperor = emperor; } }
hbm配置文件:
<hibernate-mapping> <class name="bi.one2many.Emperor"> <id name="id" column="did"> <generator class="native" /> </id> <property name="name" type="string" column="name"></property> <!-- confirure the uniredirection association --> <set name="ministers" inverse="true" cascade="all"> <key column="did" not-null="true"></key> <one-to-many class="bi.one2many.Minister"/> </set> </class> </hibernate-mapping> <hibernate-mapping> <class name="bi.one2many.Minister"> <id name="id" column="mid"> <generator class="native" /> </id> <property name="name" type="string" column="name"></property> <many-to-one name="emperor" column="did" cascade="all"></many-to-one> </class> </hibernate-mapping>
測試文件:
public class Test { @org.junit.Test public void testAdd() { SessionFactory sf = HibernateUtil.getSessionFactory(); Session session = sf.getCurrentSession(); session.beginTransaction(); Minister m1 = new Minister(); m1.setName("廉頗"); Minister m2 = new Minister(); m2.setName("藺相如"); Emperor emperor = new Emperor(); emperor.setName("齊威王"); //emperor.getMinisters().add(m1); //session.save(emperor); m1.setEmperor(emperor); m2.setEmperor(emperor); session.save(m1); session.save(m2); session.beginTransaction().commit(); } }
測試結果:
Hibernate: insert into Emperor (name) values (?) Hibernate: insert into Minister (name, did) values (?, ?) Hibernate: insert into Minister (name, did) values (?, ?)
在雙向關聯關系配置中有inverse屬性和cascade屬性比較讓人迷糊,不過參看一下這個文章寫得蠻清楚的:
Hibernate中的Inverse和cascade屬性配置
http://www.cnblogs.com/focusj/archive/2011/03/23/2057603.html。