HQL(九)接続クエリー

4669 ワード

C++ c ハイベルナー同前 JUnit

接続クエリー(重要)
*内部接続
*外部ジョイン(左/右)
参照:JoinQueryTest.java
内部接続は3種類あります:inner join,join,"="


package com.wlh.hibernate;

import java.util.Iterator;
import java.util.List;

import junit.framework.TestCase;

import org.hibernate.Session;

public class JoinQueryTest extends TestCase{
	
	/**
	 *    
	 */
	public void testQuery1() {
		Session session = null;
		try {
			session = HibernateUtils.getSession();
			session.beginTransaction();
			 //====   join==========//
			List students=session.createQuery("select s.name ,c.name from Student s join s.classes c").list();
			for(Iterator iter=students.iterator();iter.hasNext();){
				Object [] o=(Object [])iter.next();
				System.out.println("id="+o[0]+",o[1]"+o[0]);
			}
			session.getTransaction().commit();
		}catch(Exception e) {
			e.printStackTrace();
			session.getTransaction().rollback();
		}finally {
			HibernateUtils.closeSession(session);
		}
	}	
	
	/**
	 *    
	 */
	public void testQuery2() {
		Session session = null;
		try {
			session = HibernateUtils.getSession();
			session.beginTransaction();
			 //=======   inner join        ，  inner    ，     ======//
			List students=session.createQuery("select s.name, c.name from Student s inner join s.classes c").list();
			for(Iterator iter=students.iterator();iter.hasNext();){
				Object [] o=(Object [])iter.next();
				System.out.println("id="+o[0]+",o[1]"+o[0]);
			}
			session.getTransaction().commit();
		}catch(Exception e) {
			e.printStackTrace();
			session.getTransaction().rollback();
		}finally {
			HibernateUtils.closeSession(session);
		}
	}	
	
	/**
	 *    
	 */
	public void testQuery3() {
		Session session = null;
		try {
			session = HibernateUtils.getSession();
			session.beginTransaction();
			//=========== "="    ===========//
			List students=session.createQuery("select s.name ,c.name from Student s ,Classes c where s.classes.id=c.id").list();
			for(Iterator iter=students.iterator();iter.hasNext();){
				Object [] o=(Object [])iter.next();
				System.out.println("id="+o[0]+",o[1]"+o[0]);
			}
			session.getTransaction().commit();
		}catch(Exception e) {
			e.printStackTrace();
			session.getTransaction().rollback();
		}finally {
			HibernateUtils.closeSession(session);
		}
	}	
	

[b][color=red]   ：    2            [/color]	[/b]
         


  
    /**
	 *    
	 */
	public void testQuery4() {
		Session session = null;
		try {
			session = HibernateUtils.getSession();
			session.beginTransaction();
			//        （         ）
			List students=session.createQuery("select s.name ,c.name from Student s  left join s.classes c").list();
			for(Iterator iter=students.iterator();iter.hasNext();){
				Object [] o=(Object [])iter.next();
				System.out.println("id="+o[0]+",o[1]="+o[1]);
			}
			session.getTransaction().commit();
		}catch(Exception e) {
			e.printStackTrace();
			session.getTransaction().rollback();
		}finally {
			HibernateUtils.closeSession(session);
		}
	}	
	
	
	
	/**
	 *    
	 */
	public void testQuery5() {
		Session session = null;
		try {
			session = HibernateUtils.getSession();
			session.beginTransaction();
			//        ，（         ）
			List students=session.createQuery("select s.name ,c.name from Student s  right join s.classes c").list();
			for(Iterator iter=students.iterator();iter.hasNext();){
				Object [] o=(Object [])iter.next();
				System.out.println("id="+o[0]+",o[1]="+o[1]);
			}
			session.getTransaction().commit();
		}catch(Exception e) {
			e.printStackTrace();
			session.getTransaction().rollback();
		}finally {
			HibernateUtils.closeSession(session);
		}
	}	
	
	
}

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