Hibernate关系映射(7)_多对一单向关联

一.Annotation方式：

 　

 User与Group是多对一的关系。在多的一方User持有Group的引用

    /* * Group.java */@Entity@Table(name="t_group")public class Group {private int id;private String name;@Id@GeneratedValuepublic 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;}}  

 

/* * User.java */@Entity@Table(name="t_user")public class User {private int id;private String name;private Group group;@Id@GeneratedValuepublic int getId() {return id;}@ManyToOne　　　　 @JoinColumn(name="groupId") public Group getGroup() {return group;}public void setGroup(Group group) {this.group = group;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}}

 

 

二.XML方式：(以上程序去掉注解)

  

在Group.hbm.xml中配置映射关系：

<hibernate-mapping><class name="com.szy.hibernate.model.Group" table="t_group"><id name="id"><generator class="native"></generator></id><property name="name"></property> </class></hibernate-mapping>

 

 

在User.hbm.xml中配置映射关系：

<hibernate-mapping><class name="com.szy.hibernate.model.User" table="t_user"><id name="id"><generator class="native"></generator></id><property name="name"></property><many-to-one name="group" column="groupId"></many-to-one> </class></hibernate-mapping>