标签：hibernate
一对一映射一共有两种映射方式:
使用用户和身份证信息的一对一的关系
User:
package cn.itcast.one2one;
public class User {
private int userId;//用户id
private String userName;//用户姓名
private IdCard idCard;//身份者
public int getUserId() {
return userId;
}
public void setUserId(int userId) {
this.userId = userId;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public IdCard getIdCard() {
return idCard;
}
public void setIdCard(IdCard idCard) {
this.idCard = idCard;
}
}
IdCard:
package cn.itcast.one2one;
public class IdCard {
private int user_id;//
private int cardNum;//身份证号码
private String place;//出生地
private User user;
public int getUser_id() {
return user_id;
}
public void setUser_id(int user_id) {
this.user_id = user_id;
}
public int getCardNum() {
return cardNum;
}
public void setCardNum(int cardNum) {
this.cardNum = cardNum;
}
public String getPlace() {
return place;
}
public void setPlace(String place) {
this.place = place;
}
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
}
<?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping package="cn.itcast.one2one" auto-import="true"> <class name="User" table="t_user"> <id name="userId"> <generator class="native"></generator> </id> <property name="userName" length="20"></property> <!-- 一对一映射： 没有外键方 --> <one-to-one name="idCard" class="IdCard" cascade="save-update"></one-to-one> </class> </hibernate-mapping>IdCard.hbm.xml文件
<?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping package="cn.itcast.one2one" auto-import="true"> <class name="IdCard" table="t_IdCard"> <id name="cardNum"> <generator class="assigned"></generator> </id> <property name="place" length="20"></property> <!-- 一对一映射，有外键方 unique="true" 给外键字段添加唯一约束 --> <many-to-one name="user" unique="true" column="user_id" class="User" cascade="save-update"></many-to-one> </class> </hibernate-mapping>
<?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping package="cn.itcast.one2one" auto-import="true"> <class name="User" table="t_user"> <id name="userId"> <generator class="native"></generator> </id> <property name="userName" length="20"></property> <!-- 一对一映射： 没有外键方 --> <one-to-one name="idCard" class="IdCard" cascade="save-update"></one-to-one> </class> </hibernate-mapping>IdCard.hbm.xml文件
<?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping package="cn.itcast.c_one2one2"> <class name="IdCard" table="t_Idcard"> <id name="user_id"> <!-- id 节点指定的是主键映射, 即user_id是主键 主键生成方式： foreign 即把别的表的主键作为当前表的主键； property (关键字不能修改)指定引用的对象 对象的全名 cn..User、 对象映射 cn.User.hbm.xml、 table(id) --> <generator class="foreign"> <param name="property">user</param> </generator> </id> <property name="cardNum" length="20"></property> <property name="place" length="20"></property> <!-- 一对一映射，有外键方 （基于主键的映射） constrained="true" 指定在主键上添加外键约束 --> <one-to-one name="user" class="User" constrained="true" cascade="save-update"></one-to-one> </class> </hibernate-mapping>
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标签：hibernate
原文地址：http://blog.csdn.net/u014010769/article/details/47114751
