7.hibernat实现双向一对多(多对一)

 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">scott</property>
 8      <property name="connection.password">tiger</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/Dept.hbm.xml"/>
14      <mapping resource="com/entity/Emp.hbm.xml"/>
15   </session-factory>
16 </hibernate-configuration>

 1 package com.entity;
 2 
 3 import java.util.HashSet;
 4 import java.util.Set;
 5 
 6 public class Dept {
 7     /**
 8      * 部门编号
 9      */
10     private int deptno;
11     /**
12      * 部门名称
13      */
14     private String dname;
15     /**
16      * 部门位置
17      */
18     private String loc;
19     /**
20      * 创建set集合
21      */
22     private Set<Emp> empset=new HashSet<Emp>();
23     
24     public Dept() {
25     }
26     public Dept(int deptno, String dname, String loc) {
27         this.deptno = deptno;
28         this.dname = dname;
29         this.loc = loc;
30     }
31     
32     public Dept(int deptno, String dname, String loc, Set<Emp> empset) {
33         this.deptno = deptno;
34         this.dname = dname;
35         this.loc = loc;
36         this.empset = empset;
37     }
38     public int getDeptno() {
39         return deptno;
40     }
41     public void setDeptno(int deptno) {
42         this.deptno = deptno;
43     }
44     public String getDname() {
45         return dname;
46     }
47     public void setDname(String dname) {
48         this.dname = dname;
49     }
50     public String getLoc() {
51         return loc;
52     }
53     public void setLoc(String loc) {
54         this.loc = loc;
55     }
56     
57     public Set<Emp> getEmpset() {
58         return empset;
59     }
60     public void setEmpset(Set<Emp> empset) {
61         this.empset = empset;
62     }
63     @Override
64     public String toString() {
65         return "Dept [deptno=" + deptno + ", dname=" + dname + ", empset="
66                 + empset + ", loc=" + loc + "]";
67     }
68     
69 
70 }

  1 package com.entity;
  2 
  3 import java.util.Date;
  4 
  5 public class Emp {
  6     /**
  7      * 员工编号
  8      */
  9     private Integer empno;
 10     /**
 11      * 员工姓名
 12      */
 13     private String ename;
 14     /**
 15      * 员工工作
 16      */
 17     private String job;
 18     /**
 19      * 员工领导编号
 20      */
 21     private Integer mgr;
 22     /**
 23      * 员工雇佣日期
 24      */
 25     private Date hiredate;
 26     /**
 27      * 员工工资
 28      */
 29     private Integer sal;
 30     /**
 31      * 员工奖金
 32      */
 33     private Integer comm;
 34     /**
 35      * 部门外键
 36      * 引入部门对象
 37      */
 38     private Dept dept;
 39     public Emp() {
 40         super();
 41     }
 42     public Emp(Integer empno, String ename, String job, Integer mgr,
 43             Date hiredate, Integer sal, Integer comm, Dept dept) {
 44         this.empno = empno;
 45         this.ename = ename;
 46         this.job = job;
 47         this.mgr = mgr;
 48         this.hiredate = hiredate;
 49         this.sal = sal;
 50         this.comm = comm;
 51         this.dept = dept;
 52     }
 53     
 54     public Integer getEmpno() {
 55         return empno;
 56     }
 57     public void setEmpno(Integer empno) {
 58         this.empno = empno;
 59     }
 60     public String getEname() {
 61         return ename;
 62     }
 63     public void setEname(String ename) {
 64         this.ename = ename;
 65     }
 66     public String getJob() {
 67         return job;
 68     }
 69     public void setJob(String job) {
 70         this.job = job;
 71     }
 72     public Integer getMgr() {
 73         return mgr;
 74     }
 75     public void setMgr(Integer mgr) {
 76         this.mgr = mgr;
 77     }
 78     public Date getHiredate() {
 79         return hiredate;
 80     }
 81     public void setHiredate(Date hiredate) {
 82         this.hiredate = hiredate;
 83     }
 84     public Integer getSal() {
 85         return sal;
 86     }
 87     public void setSal(Integer sal) {
 88         this.sal = sal;
 89     }
 90     public Integer getComm() {
 91         return comm;
 92     }
 93     public void setComm(Integer comm) {
 94         this.comm = comm;
 95     }
 96     public Dept getDept() {
 97         return dept;
 98     }
 99     public void setDept(Dept dept) {
100         this.dept = dept;
101     }
102     @Override
103     public String toString() {
104         return "Emp [comm=" + comm + ", dept=" + dept + ", empno=" + empno
105                 + ", ename=" + ename + ", hiredate=" + hiredate + ", job="
106                 + job + ", mgr=" + mgr + ", sal=" + sal + "]";
107     }
108     
109     
110     
111     
112     
113 
114 }

 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.Dept" table="DEPT" schema="SCOTT" lazy="true">
 5   <!-- 主键配置 -->
 6    <id name="deptno" type="java.lang.Integer" column="DEPTNO">
 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="dname" type="java.lang.String" column="DNAME"/>
12    
13    <!-- 部门位置 -->
14    <property name="loc" type="java.lang.String" column="LOC"/>
15    
16    <!-- 
17      一对多映射  
18      cascade级联：操作主表时同时操作从表
19    cascade="save-update" 级联增和该
20    cascade="delete" 级联删除
21    cascade="none" 忽略关联
22    cascade="all"级联增删改
23    -->
24    <!-- inverse="false"主动维护关联关系，false主动方，true被动方（当从表修改时，主表不修改）
25    inverse="false"两条update
26    inverse="true" 一条update -->
27    <set name="empset" cascade="all" inverse="true" order-by="ename asc">
28       <!-- 本表主键列，对应emp的外键列 -->
29       <key column="DEPTNO"></key>
30       <!-- 集合存储的数据类型 -->
31       <one-to-many class="com.entity.Emp"/>
32    </set>
33 </class>
34 </hibernate-mapping>

 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.Emp" table="EMP" schema="scott" >
 5       <id name="empno" type="java.lang.Integer" column="EMPNO">
 6          <generator class="assigned"/>
 7       </id>
 8       <property name="ename" type="java.lang.String" column="ENAME"/>
 9       <property name="job" type="java.lang.String" column="JOB"/>
10       <property name="mgr" type="java.lang.Integer" column="MGR"/>
11       <property name="hiredate" type="java.util.Date" column="HIREDATE"/>
12       <property name="sal" type="java.lang.Integer" column="SAL"/>
13       <property name="comm" type="java.lang.Integer" column="COMM" not-null="false" />
14       
15       <!-- 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 -->
16       <many-to-one name="dept" class="com.entity.Dept" column="DEPTNO"/>   
17    </class>
18 </hibernate-mapping>

  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.Dept;
 15 import com.entity.Emp;
 16 import com.util.HibernateUtil;
 17 
 18 public class DeptDao {
 19     
 20     public static void main(String[] args) {
 21         System.out.println("--------------------1.保存：部门对象，插入2条，修改1条------------------");
 22         //saveDept();
 23         System.out.println("----------------2.删除部门数据级联删除员工--------------------------------------");
 24     //    deleteDept(4);
 25         System.out.println("----------------3.修改员工--------------------------------------");
 26         //updateEmp(2,1);
 27         System.out.println("-------------------4.查询某部门下的所有员工，并按姓名排序order-by-------------------------------------");
 28         //getEmpByDeptno(10);
 29         System.out.println("-------------------5.查询某部门信息--lazy=false-----------------------------------");
 30         //getDeptByDeptno(10);
 31         System.out.println("-------------------6.查询某部门信息--lazy=true-----------------------------------");
 32         saveEmp(10);
 33         
 34     }
 35     /**
 36      * -6.查询某部门信息--lazy=true懒加载  ，查的时候用load懒加载查询的方式
 37      * @param id
 38      */
 39     private static void saveEmp(int id) {
 40           Session session=HibernateUtil.getSession();
 41           Transaction tx=session.beginTransaction();
 42             
 43             //查单条load懒加载
 44             Dept dept=(Dept) session.load(Dept.class, id);
 45             Date date=null;
 46             try {
 47                 date = new SimpleDateFormat("yyyy-MM-dd").parse("2013-3-3");
 48             } catch (ParseException e) {
 49                 e.printStackTrace();
 50             }
 51             Emp emp=new Emp(6, "holly", "教员", 2, date, 2300, 200, dept);
 52             
 53             //添加员工信息
 54             session.save(emp);
 55             tx.commit();
 56             System.out.println("添加成功");
 57             
 58             HibernateUtil.closeSession();
 59         
 60     }
 61     /**
 62      * 5.查询某部门信息
 63      * dept类级别的lazy=false 立即加载  ，查的时候用get立即加载的方式
 64      * 1条查询sql
 65      * @param i
 66      */
 67     private static void getDeptByDeptno(int id) {
 68         Session session=HibernateUtil.getSession();
 69         
 70         //查单条
 71         Dept dept=(Dept) session.load(Dept.class, id);
 72         
 73         HibernateUtil.closeSession();
 74         
 75     }
 76     /**
 77      * 4.查询某部门下的所有员工，并按姓名排序order-by
 78      * @param i
 79      */
 80     private static void getEmpByDeptno(int id) {
 81         Session session=HibernateUtil.getSession();
 82         
 83         //查单条
 84         Dept dept=(Dept) session.get(Dept.class, id);
 85         Set<Emp> emps=dept.getEmpset();
 86         for (Emp emp : emps) {
 87             System.out.println(emp.getEname());
 88         }
 89         HibernateUtil.closeSession();
 90         
 91     }
 92   /**
 93    * 3.修改员工
 94    * @param empno
 95    * @param deptno
 96    */
 97     private static void updateEmp(int empno,int deptno) {
 98         Session session=HibernateUtil.getSession();
 99         //2.开启事务
100         Transaction tx=session.beginTransaction();
101         //查单条
102         Dept dept=(Dept) session.load(Dept.class, deptno);
103         Emp emp=(Emp) session.load(Emp.class, empno);
104         /*
105          * 监测到Emp对象的属性发生变化，所以执行
106          *  update
107         scott.EMP 
108      set
109         ENAME=?,
110         JOB=?,
111         MGR=?,
112         HIREDATE=?,
113         SAL=?,
114         COMM=?,
115         DEPTNO=? 
116     where
117         EMPNO=?
118          */
119         emp.setDept(dept);
120     /*(inverse=false)主动，监测到Dept对象的属性发生变化，所以执行
121         update
122         scott.EMP 
123         set
124             DEPTNO=? 
125         where
126             EMPNO=?
127       (inverse=true)被动，没有上面一条update      
128       */
129         dept.getEmpset().add(emp);
130         System.out.println("修改成功");
131         
132         tx.commit();
133         HibernateUtil.closeSession();
134         
135     }
136 
137     /**
138      * 2.删除
139      * @param id
140      */
141     private static void deleteDept(int id) {
142         Session session=HibernateUtil.getSession();
143         //2.开启事务
144         Transaction tx=session.beginTransaction();
145         //查单条
146         Dept dept=(Dept) session.get(Dept.class, id);
147         if(dept!=null){
148             session.delete(dept);
149             System.out.println("删除成功");
150         }else{
151             System.out.println("该条数据不存在");
152         }
153         tx.commit();
154         HibernateUtil.closeSession();
155         
156     }
157 
158     /**
159      * 1.保存：1部门和2员工-----3条sql
160      */
161     private static void saveDept() {
162         //1.开启Session
163         Session session=HibernateUtil.getSession();
164         
165         //2.开启事务
166         Transaction tx=session.beginTransaction();
167         
168         //3.执行操作
169         //创建部门对象
170         Dept dept=new Dept(3, "教职部", "安德门");
171         Date date=null;
172         try {
173             date = new SimpleDateFormat("yyyy-MM-dd").parse("2013-3-3");
174         } catch (ParseException e) {
175             e.printStackTrace();
176         }
177         
178         //创建员工对象
179         Emp emp1=new Emp(4, "holly", "教员", 2, date, 2300, 200, dept);
180         
181         //向集合总添加员工信息（1条sql）
182         dept.getEmpset().add(emp1);
183         
184         //保存Dept对象(2条插入)
185         session.save(dept);
186         
187         //4.提交事务
188         tx.commit();
189         System.out.println("Emp保存成功");
190         
191         //5.关闭Session
192         HibernateUtil.closeSession();
193     }
194 
195 }