9.hibernate的一对一映射

一、hibernate的一对一按照外键映射

1.创建如下sql脚本：

 1 --员工账号表
 2 create table USERS1
 3 (
 4   USERID   NUMBER(6) not null,
 5   USERNAME VARCHAR2(20),
 6   USERPASS VARCHAR2(20)
 7 )
 8 ;
 9 
10 
11 
12 --档案表
13 create table RESUME1
14 (
15   RESID     NUMBER(6) not null,
16   RESUSERID NUMBER(6),
17   RESNAME   VARCHAR2(20),
18   RESCARDNO VARCHAR2(20)
19 )
20 ;
21 
22 alter table USERS1
23   add constraint PK_USERS1_USERID primary key (USERID);
24 
25 alter table RESUME1
26   add constraint PK_RESUME1_RESID primary key (RESID);
27 alter table RESUME1
28   add constraint FK_RESUME1_RESUSERID foreign key (RESUSERID)
29   references USERS1 (USERID);
fk_one_to_one_.sql

2.创建如下web项目结构

3.在项目的src根目录下创建主配置文件hibernate.cfg.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd" >
 3 <hibernate-configuration>
 4   <session-factory>
 5      <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
 6      <property name="connection.url">jdbc:oracle:thin:@127.0.0.1:1521:orcl</property>
 7      <property name="connection.username">holly</property>
 8      <property name="connection.password">sys</property>
 9      <property name="dialect">org.hibernate.dialect.Oracle10gDialect</property>
10      <property name="show_sql">true</property>
11      <property name="format_sql">true</property>
12      
13      <mapping resource="com/entity/Resume1.hbm.xml"/>
14      <mapping resource="com/entity/Users1.hbm.xml"/>
15   </session-factory>
16 </hibernate-configuration>
hibernate.cfg.xml

4.在项目的src的com.entity包下创建Users1.java类

 1 package com.entity;
 2 
 3 import java.util.HashSet;
 4 import java.util.Set;
 5 /**
 6  * 员工账号表
 7  * @author Dell
 8  *
 9  */
10 public class Users1 {
11     private Integer userid;  //员工账号id
12     private String username;  //员工姓名
13     private String userpass; //员工账号密码
14     private Resume1 resume1;  //档案对象
15     
16     public Users1() {
17     }
18     public Users1(Integer userid, String username, String userpass) {
19         this.userid = userid;
20         this.username = username;
21         this.userpass = userpass;
22     }
23     public Users1(Integer userid, String username, String userpass,
24             Resume1 resume1) {
25         this.userid = userid;
26         this.username = username;
27         this.userpass = userpass;
28         this.resume1 = resume1;
29     }
30     public Integer getUserid() {
31         return userid;
32     }
33     public void setUserid(Integer userid) {
34         this.userid = userid;
35     }
36     public String getUsername() {
37         return username;
38     }
39     public void setUsername(String username) {
40         this.username = username;
41     }
42     public String getUserpass() {
43         return userpass;
44     }
45     public void setUserpass(String userpass) {
46         this.userpass = userpass;
47     }
48     
49     public Resume1 getResume1() {
50         return resume1;
51     }
52     public void setResume1(Resume1 resume1) {
53         this.resume1 = resume1;
54     }
55     @Override
56     public String toString() {
57         return "Users1 [resume1=" + resume1 + ", userid=" + userid
58                 + ", username=" + username + ", userpass=" + userpass + "]";
59     }
60     
61     
62 
63 }
Users1.java

5.在项目的src的com.entity包下创建Users1.hbm.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >
 3 <hibernate-mapping>
 4    <class name="com.entity.Users1" table="USERS1" schema="HOLLY" >
 5       <id name="userid" type="java.lang.Integer" column="USERID">
 6          <generator class="assigned"/>
 7       </id>
 8       <property name="username" type="java.lang.String" column="USERNAME"/>
 9       <property name="userpass" type="java.lang.String" column="USERPASS"/>
10      
11       
12       <!-- 多对一映射：name是emp中外键字段引用的对象，class是对象的类型，column是数据库中对应的外键列字段名 -->
13       <one-to-one name="resume1" class="com.entity.Resume1" property-ref="users1"/>   
14    </class>
15 </hibernate-mapping>
Users1.hbm.xml

6.在项目的src的com.entity包下创建Resume1.java类

 1 package com.entity;
 2 
 3 import java.util.Date;
 4 /**
 5  * 档案表
 6  * @author Dell
 7  *
 8  */
 9 public class Resume1 {
10     private Integer resid; //档案编号
11     private Users1 users1;  //用户对象
12     private String resname;  //档案名称
13     private String rescardno; //档案卡号
14     
15     public Resume1() {
16     }
17 
18     
19     public Resume1(Integer resid, String resname, String rescardno) {
20         this.resid = resid;
21         this.resname = resname;
22         this.rescardno = rescardno;
23     }
24 
25 
26     public Resume1(Integer resid, Users1 users1, String resname,
27             String rescardno) {
28         this.resid = resid;
29         this.users1 = users1;
30         this.resname = resname;
31         this.rescardno = rescardno;
32     }
33 
34     public Integer getResid() {
35         return resid;
36     }
37 
38     public void setResid(Integer resid) {
39         this.resid = resid;
40     }
41 
42     public Users1 getUsers1() {
43         return users1;
44     }
45 
46     public void setUsers1(Users1 users1) {
47         this.users1 = users1;
48     }
49 
50     public String getResname() {
51         return resname;
52     }
53 
54     public void setResname(String resname) {
55         this.resname = resname;
56     }
57 
58     public String getRescardno() {
59         return rescardno;
60     }
61 
62     public void setRescardno(String rescardno) {
63         this.rescardno = rescardno;
64     }
65 
66     @Override
67     public String toString() {
68         return "Resume1 [rescardno=" + rescardno + ", resid=" + resid
69                 + ", resname=" + resname + ", users1=" + users1 + "]";
70     }
71     
72     
73     
74     
75 
76 }
Resume1.java

7.在项目的src的com.entity包下创建Resume1.hbm.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >
 3 <hibernate-mapping>
 4 <class name="com.entity.Resume1" table="RESUME1" schema="holly">
 5   <!-- 主键配置 -->
 6    <id name="resid" type="java.lang.Integer" column="RESID">
 7       <!-- 主键由应用程序负责生成 -->
 8       <generator class="assigned"/> 
 9    </id>
10    <!-- 部门名称 -->
11    <property name="resname" type="java.lang.String" column="RESNAME"/>
12    
13    <!-- 部门位置 -->
14    <property name="rescardno" type="java.lang.String" column="RESCARDNO"/>
15    <!-- 一个个档案对应一个人 -->
16    <!-- unique表示唯一约束，确保用户唯一 unique=true表示一一对应 -->
17   <many-to-one name="users1" class="com.entity.Users1" column="RESUSERID" cascade="all" unique="true"/>
18 </class>
19 </hibernate-mapping>
Resume1.hbm.xml

8.在项目的src的ccom.util包下创建HibernateUtil.java

 1 package com.util;
 2 
 3 import org.hibernate.HibernateException;
 4 import org.hibernate.Session;
 5 import org.hibernate.SessionFactory;
 6 import org.hibernate.cfg.Configuration;
 7 
 8 public class HibernateUtil {
 9     /**
10      * 创建线程池来管理Session
11      */
12     private static ThreadLocal<Session> thread=new ThreadLocal<Session>();
13     /**
14      * 创建读取配置文件的对象
15      */
16     private static Configuration config=null;
17     /**
18      * 创建获取Session的工厂
19      */
20     private static SessionFactory factory=null;
21     
22     /**
23      * 读取配置文件
24      */
25     static{
26         try {
27             config=new Configuration().configure("/hibernate.cfg.xml");
28             factory=config.buildSessionFactory();
29         } catch (HibernateException e) {
30             System.out.println("读取配置文件或创建SessionFactory失败！");
31             e.printStackTrace();
32         }
33     }
34     
35     /**
36      * 获取session
37      * @return
38      */
39     public static Session getSession(){
40         Session session=thread.get();
41         if(session==null){
42             session=factory.openSession();
43             thread.set(session);
44         }
45         return session;
46     }
47     
48     /**
49      * 关闭Session
50      */
51     public static void closeSession(){
52         Session session=thread.get();
53         thread.set(null);
54         session.close();
55     }
56     
57 
58 }
HibernateUtil.java

9.在项目的src的com.dao包下创建Resume1Dao.java

 1 package com.dao;
 2 
 3 import java.text.ParseException;
 4 import java.text.SimpleDateFormat;
 5 import java.util.Date;
 6 import java.util.List;
 7 import java.util.Set;
 8 import java.util.logging.SimpleFormatter;
 9 
10 import org.hibernate.Query;
11 import org.hibernate.Session;
12 import org.hibernate.Transaction;
13 
14 import com.entity.Users1;
15 import com.entity.Resume1;
16 import com.util.HibernateUtil;
17 
18 public class Resume1Dao {
19     
20     public static void main(String[] args) {
21         //saveResume1();
22         loadResume1();
23         
24     }
25     /**
26      * 2.立即加载：当查询档案信息时查询账号信息
27      *
28      */
29     private static void loadResume1() {
30           Session session=HibernateUtil.getSession();
31           Resume1 resume1=(Resume1) session.get(Resume1.class, 1);
32           System.out.println("姓名："+resume1.getResname());
33           System.out.println("用户名："+resume1.getUsers1().getUsername());
34           
35           HibernateUtil.closeSession();
36         
37     }
38     /**
39      * 1.一对一 按照外键映射：级联操作，保存档案信息时，保存员工账号信息
40      * 1条查询sql，2条插入sql,查询sql见readme.txt
41      */
42     private static void saveResume1() {
43           Session session=HibernateUtil.getSession();
44            Transaction tx=session.beginTransaction();
45            //创建员工档案对象
46            Resume1 resume1=new Resume1(1, "李四", "2014010101010");
47            
48            //创建员工账户信息
49            Users1 users1=new Users1(1, "lisi", "123");
50            
51            //给员工档案的users1对象赋值
52            resume1.setUsers1(users1);
53            
54            //给员工账号的resume1对象赋值
55            users1.setResume1(resume1);
56            
57             //添加员工档案信息时级联保存员工账号信息
58             session.save(resume1);
59             tx.commit();
60             System.out.println("添加成功");
61             
62             HibernateUtil.closeSession();
63         
64     }
65     
66 }
Resume1Dao.java

10.运行结果如下：

 1 /**
 2      * 1.一对一 按照外键映射：级联操作，保存档案信息时，保存员工账号信息
 3      * 1条查询sql，2条插入sql,查询sql见readme.txt
 4      * 
 5      */
 6 Hibernate: 
 7     select
 8         users1x_.USERID,
 9         users1x_.USERNAME as USERNAME1_,
10         users1x_.USERPASS as USERPASS1_ 
11     from
12         HOLLY.USERS1 users1x_ 
13     where
14         users1x_.USERID=?
15 Hibernate: 
16     insert 
17     into
18         HOLLY.USERS1
19         (USERNAME, USERPASS, USERID) 
20     values
21         (?, ?, ?)
22 Hibernate: 
23     insert 
24     into
25         holly.RESUME1
26         (RESNAME, RESCARDNO, RESUSERID, RESID) 
27     values
28         (?, ?, ?, ?)
29  /**
30      * 2.立即加载：当查询档案信息时查询账号信息
31      */
32      
33 Hibernate: 
34     select
35         resume1x0_.RESID as RESID0_0_,
36         resume1x0_.RESNAME as RESNAME0_0_,
37         resume1x0_.RESCARDNO as RESCARDNO0_0_,
38         resume1x0_.RESUSERID as RESUSERID0_0_ 
39     from
40         holly.RESUME1 resume1x0_ 
41     where
42         resume1x0_.RESID=?
43 姓名：李四
44 Hibernate: 
45     select
46         users1x0_.USERID as USERID1_1_,
47         users1x0_.USERNAME as USERNAME1_1_,
48         users1x0_.USERPASS as USERPASS1_1_,
49         resume1x1_.RESID as RESID0_0_,
50         resume1x1_.RESNAME as RESNAME0_0_,
51         resume1x1_.RESCARDNO as RESCARDNO0_0_,
52         resume1x1_.RESUSERID as RESUSERID0_0_ 
53     from
54         HOLLY.USERS1 users1x0_ 
55     left outer join
56         holly.RESUME1 resume1x1_ 
57             on users1x0_.USERID=resume1x1_.RESUSERID 
58     where
59         users1x0_.USERID=?
60 Hibernate: 
61     select
62         resume1x0_.RESID as RESID0_0_,
63         resume1x0_.RESNAME as RESNAME0_0_,
64         resume1x0_.RESCARDNO as RESCARDNO0_0_,
65         resume1x0_.RESUSERID as RESUSERID0_0_ 
66     from
67         holly.RESUME1 resume1x0_ 
68     where
69         resume1x0_.RESUSERID=?
70 用户名：lisi
71
readme.txt

 二、Hibernate一对一按照主键查询

1.创建如下sql语句

 1 create table RESUME2
 2 (
 3   RESID     NUMBER(6) not null,
 4   RESNAME   VARCHAR2(20),
 5   RESCARDNO VARCHAR2(20)
 6 )
 7 ;
 8 
 9 
10 create table USERS2
11 (
12   USERID   NUMBER(6) not null,
13   USERNAME VARCHAR2(20) not null,
14   USERPASS VARCHAR2(20) not null
15 )
16 ;
17 
18 alter table RESUME2
19   add constraint PK_RESUME2_RESID primary key (RESID);
20 
21 
22 alter table USERS2
23   add constraint PK_USERS2_USERID primary key (USERID)
24   disable;
25 alter table USERS2
26   add constraint FK_USERS2_USERID foreign key (USERID)
27   references RESUME2 (RESID);
pk_one_to_one_.sql

2.项目的主配置，工具类，实体类都和上面一样，此处省略

3.在com.entity包下编辑Users2.hbm.xml映射文件

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >
 3 <hibernate-mapping>
 4 <class name="com.pojo.Users2" table="USERS2">
 5   <id name="usersid" type="java.lang.Integer" column="USERSID">
 6     <!-- 双向一对一:按照外键关联映射配置 -->
 7     <generator class="foreign">
 8       <!-- 当前类User2外键列所关联的另一方Resume2类的对象属性名resume2 -->
 9        <param name="property">resume2</param>
10     </generator>
11   </id>
12   <property name="usersname" type="java.lang.String" column="USERSNAME"/>
13   <property name="userspwd" type="java.lang.String" column="USERSPWD"/>
14   
15   <!-- 当前users2表中的usersid列又作为主键,又作为外键 -->
16   <one-to-one name="resume2" class="com.pojo.Resume2" 
17   constrained="true" cascade="all"/>
18 </class>
19 </hibernate-mapping>
Users2.hbm.xml

4.在com.entity包下编辑Resume2.hbm.xml映射文件

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >
 3 <hibernate-mapping>
 4 <class name="com.pojo.Resume2" table="RESUME2">
 5   <id name="resid" type="java.lang.Integer" column="RESID">
 6     <generator class="assigned"/>
 7   </id>
 8   <property name="resname" type="java.lang.String" column="RESNAME"/>
 9   <property name="rescard" type="java.lang.String" column="RESCARD"/>
10    
11   <one-to-one name="users2" class="com.pojo.Users2"/> 
12 
13 </class>
14 </hibernate-mapping>
Resume2.hbm.xml

5.在com.dao包下创建Test.java

 1 package com.test;
 2 
 3 import org.hibernate.Session;
 4 
 5 import com.pojo.Resume2;
 6 import com.pojo.Users2;
 7 import com.util.HibernateUtil;
 8 
 9 
10 public class Test {
11     public static void main(String[] args) {
12          //1.级联添加操作
13          //saveResumeToUsers();
14          //2.根据主键查询
15          loadResume();
16 
17     }
18     /**
19      * 1.级联添加操作
20 Hibernate: select resume2x_.RESID, resume2x_.RESNAME as RESNAME0_, resume2x_.RESCARD as RESCARD0_ from RESUME2 resume2x_ where resume2x_.RESID=?
21 Hibernate: insert into RESUME2 (RESNAME, RESCARD, RESID) values (?, ?, ?)
22 Hibernate: insert into USERS2 (USERSNAME, USERSPWD, USERSID) values (?, ?, ?)
23      */
24     private static void saveResumeToUsers() {
25         //1.获取session对象
26         Session session=HibernateUtil.getSession();
27         
28         //2.创建瞬时对象
29         Users2 users1=new Users2(3, "倩倩", "123");
30         Resume2 resume1=new Resume2(3, "倩倩档案", "qianqian320112");
31         
32         users1.setResume2(resume1);
33         resume1.setUsers2(users1);
34         
35         //3.级联添加
36         session.save(users1);
37         
38         session.beginTransaction().commit();
39         //4.提交事务
40         System.out.println("save cascade success...");
41     }
42     /**
43 Hibernate: select resume2x0_.RESID as RESID0_1_, resume2x0_.RESNAME as RESNAME0_1_, resume2x0_.RESCARD as RESCARD0_1_, users2x1_.USERSID as USERSID1_0_, users2x1_.USERSNAME as USERSNAME1_0_, users2x1_.USERSPWD as USERSPWD1_0_ from RESUME2 resume2x0_ left outer join USERS2 users2x1_ on resume2x0_.RESID=users2x1_.USERSID where resume2x0_.RESID=?
44 Resume2 [rescard=qianqian320112, resid=3, resname=倩倩档案]
45 Users2 [usersid=3, usersname=倩倩, userspwd=123]
46      */
47     private static void loadResume() {
48         //1.获取session对象
49         Session session=HibernateUtil.getSession();
50         
51         //2.根据主键去查询
52         //不会出现sql,xml默认就是延时记载
53         Resume2 resume1=(Resume2) session.load(Resume2.class, 3);
54         System.out.println(resume1);
55         System.out.println(resume1.getUsers2());
56         
57         
58     }
59 
60 }
Test.java

6.运行结果如下

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原文地址：https://www.cnblogs.com/holly8/p/5774456.html