hibernate的QBC查询学习记录
只添加hibernate
package com.dao;
import java.util.Iterator;
import java.util.List;
import org.hibernate.Criteria;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.criterion.Criterion;
import org.hibernate.criterion.Expression;
import org.hibernate.criterion.Order;
import com.pojo.User;
import com.util.HibernateSessionFactory;
public class UserDAO {
//QBC查询不支持SQL查询
private Session session;
public UserDAO()
{
session=HibernateSessionFactory.getSession();
}
public void closeSession()
{
if(session.isOpen())
{
session.close();
}
}
public void search()
{
//QBC的查询方法
//1,查询全部
Criteria cr=session.createCriteria(User.class);
/* .add(Expression.gt("id", 2))
.add(Expression.not(Expression.eq("id", 6)))
.add(Expression.isNull("name"))
.add(Expression.in("name", new String[]{"金春","金娟"}))
.add(Expression.between("id", 5, 9))
.add(Expression.not(Expression.between("id", 2, 4)))
.add(Expression.like("uname", "T__").ignoreCase())
.addOrder(Order.desc("id")).setFirstResult(1).setMaxResults(10);
*/
//指定要查询的表-以类的方式书写
//定义整体模板
//添加查询条件
Criterion c1=Expression.like("name","金%");
Criterion c2=Expression.like("address","厦%");
//条件添加到模板中
cr.add(c1);
cr.add(c2);
List<User> list=cr.list();
for(Iterator<User> iter=list.iterator();iter.hasNext();)
{
User element=iter.next();
System.out.println(element.getName()+" "+element.getAddress());
}
}
/*当需要多次使用参数查询记录的时候使用此方法。在User.hbm.xml文件当中<!-- CDATA是书写格式xml文件里面的书写格式 -->
<![CDATA[
from User p where p.name like :name
]]>
</query>
</hibernate-mapping>*/
public void serachquery()
{
Query q=session.getNamedQuery("Jk");
q.setString("name", "金%");
List l=q.list();
for(Iterator<User> iter=l.iterator();iter.hasNext();)
{
User element=iter.next();
System.out.println(element.getName()+" "+element.getAddress());
}
System.out.println("集合数据量的大小，既是数据记录的条数");
System.out.println(l.size());
}
}
类映射文件User.hbm.xml文件内容如下
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!--
Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
<class name="com.pojo.User" table="user" catalog="study">
<id name="id" type="java.lang.Integer">
<column name="id" />
<generator class="assigned" />
</id>
<property name="name" type="java.lang.String">
<column name="name" length="22" not-null="true" />
</property>
<property name="address" type="java.lang.String">
<column name="address" length="32" not-null="true" />
</property>
</class>
<query name="Jk">
<!-- CDATA是书写格式xml文件里面的书写格式 -->
<![CDATA[
from User p where p.name like :name
]]>
</query>
</hibernate-mapping>
测试类test
package com.test;
import com.dao.UserDAO;
public class test {
public static void main(String[] args)
{
UserDAO dao=new UserDAO();
//dao.search();
dao.serachquery();
dao.closeSession();
}
}