复合主键的查询方法

 

映射文件都是eclipse自动生成，包括Users.java 和 UserPK.java。 这边就不贴出来了

假如USERS表的主键为NAME字段,TEL字段和AGE字段，那么在User类中也应该存在相对应的属性和方法，映射方法如下：

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
 "-//Hibernate/Hibernate Mapping DTD//EN"
 "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >

<hibernate-mapping package="classweb.model.po">
 <class
  name="Users"
  table="USERS"
 >
  <meta attribute="sync-DAO">false</meta>
  <composite-id name="id" class="UsersPK">
   <key-property
    name="name"
    column="NAME"
    type="string"
   />
   <key-property
    name="tel"
    column="TEL"
    type="string"
   />
  </composite-id>

  <property
   name="age"
   column="AGE"
   type="string"
   not-null="false"
  />
  
 </class> 
</hibernate-mapping>

以下代码生成一个Users对象，并保存．

    Session s = HibernateUtil.currentSession();
    Transaction t = s.beginTransaction();
    UsersPK usersPK = new UsersPK();
    usersPK.setName(1);
    usersPK.setTel(4);
    Users user = new Users();
    user.setAge("19");
    user.setId(usersPK );
    s.save(user);
    t.commit();
    HibernateUtil.closeSession();
    System.out.println("insert success!");

更新．

    Session s = HibernateUtil.currentSession();
    Transaction t = s.beginTransaction();
    UsersPK usersPK = new UsersPK();
    usersPK.setDbid(1);
    usersPK.setRowUID(4);
    Users user = (Users)s.load(Users.class, usersPK);

    user.setAge("20");
    s.update(user);
    t.commit();
    HibernateUtil.closeSession();
    System.out.println("update success!");

删除．

Session s = HibernateUtil.currentSession();
    Transaction t = s.beginTransaction();
    UsersPK usersPK = new UsersPK();
    usersPK.setDbid(1);
    usersPK.setRowUID(4);
    Users user = (Users)s.load(Users.class, usersPK);

    s.delete(user);
    t.commit();
    HibernateUtil.closeSession();
    System.out.println("delete success!");

最后讲select

如果对复合主键中的一个主键进行查询，必须

    Session s = HibernateUtil.currentSession();
    Criteria c = s.createCriteria(Users.class);
    c.add(Restrictions.eq("id.name", "levi"));
    List list = c.list();
    Iterator iter = list.iterator();
    while (iter.hasNext()) {
      Users item = (Users) iter.next();
      System.out.println("name:" + item.getId().getName());
      System.out.println("tel;" + item.getId().getTel());
      System.out.println("age:" + item.getAge());
    }
    HibernateUtil.closeSession();
    System.out.println("select success!");