hibernate多表查询详解

package com.fit.test; import java.io.File; import java.io.FileOutputStream; import java.util.HashSet; import java.util.Iterator; import java.util.List; import java.util.Set; import org.hibernate.Hibernate; import org.hibernate.Transaction; import org.hibernate.classic.Session; import com.fit.bean.Depterment; import com.fit.bean.Person; import com.fit.util.DBUtil; /** * * 多表查询示例如下; * @author Administrator * */ public class Test { public static void main(String[] args) { /** * 注意 ： 一定得有对应的构造函数 才能执行new Object()查询操作 */ find4(); find(); // find1(); //find2(); } public static void find(){ Session session = (Session) DBUtil.creatSession(); Transaction tx = session.beginTransaction(); try{ List<Person> list = session.createQuery("select new Person (person.person_id,person.person_name,person.dept)from Person person").list(); for (Person p : list) { System.out.println(p.getPerson_id()+"-->"+p.getPerson_name()+"-->"+p.getDept().getDept_name()); } }catch(Exception e){ e.printStackTrace(); } } public static void find4(){ Session session = (Session) DBUtil.creatSession(); Transaction tx = session.beginTransaction(); try{ List<Person> list = session.createQuery("select new Person (person.person_id,person.person_name)from Person person").list(); for (Person p : list) { System.out.println(p.getPerson_id()+"-->"+p.getPerson_name()); } }catch(Exception e){ e.printStackTrace(); } } public static void find2(){ Session session = (Session) DBUtil.creatSession(); Transaction tx = session.beginTransaction(); try{ List<Object> lists = session.createQuery("select new list ( person.person_id,person.person_name ,dept.dept_name )from Person person,Depterment dept where person.dept.dept_id =dept.dept_id ").list(); for (Object object : lists) { List list = (List) object; System.out.println(list.get(0)+"-->"+list.get(1)+"-->"+list.get(2)); } }catch(Exception e){ e.printStackTrace(); } } public static void find1(){ Session session = (Session) DBUtil.creatSession(); Transaction tx = session.beginTransaction(); try{ List<Object[]> list = session.createQuery("select person.person_id,person.person_name,dept.dept_name from Person person,Depterment dept where person.dept.dept_id =dept.dept_id ").list(); for (Object[] objects : list) { System.out.println(objects[0]+"-->"+objects[1]+"-->"+objects[2]); } }catch(Exception e){ e.printStackTrace(); } } }