simpleobjectquerytest1.java

实现一些hibernate底层的东西

package com.bjsxt.hibernate;

import java.util.Iterator;
import java.util.List;

import org.hibernate.Session;

import junit.framework.TestCase;

/**
 * 实体对象查询
 * @author Administrator
 *
 */
public class SimpleObjectQueryTest1 extends TestCase {

	public void testQuery1() {
		Session session = null;
		try {
			session = HibernateUtils.getSession();
			session.beginTransaction();
			
			//返回Student对象的集合
			//可以忽略select
			List students = session.createQuery("from Student").list();
			for (Iterator iter=students.iterator(); iter.hasNext();) {
				Student student = (Student)iter.next();
				System.out.println(student.getName());
			}
			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();
			
			//返回Student对象的集合
			//可以忽略select,表可以使用别名
			List students = session.createQuery("from Student s").list();
			for (Iterator iter=students.iterator(); iter.hasNext();) {
				Student student = (Student)iter.next();
				System.out.println(student.getName());
			}
			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();
			
			//返回Student对象的集合
			//可以忽略select,表可以使用as命名别名
			List students = session.createQuery("from Student as s").list();
			for (Iterator iter=students.iterator(); iter.hasNext();) {
				Student student = (Student)iter.next();
				System.out.println(student.getName());
			}
			session.getTransaction().commit();
		}catch(Exception e) {
			e.printStackTrace();
			session.getTransaction().rollback();
		}finally {
			HibernateUtils.closeSession(session);
		}
	}
	
	public void testQuery4() {
		Session session = null;
		try {
			session = HibernateUtils.getSession();
			session.beginTransaction();
			
			//返回Student对象的集合
			//使用select查询实体对象，必须采用别名
			List students = session.createQuery("select s from Student as s").list();
			for (Iterator iter=students.iterator(); iter.hasNext();) {
				Student student = (Student)iter.next();
				System.out.println(student.getName());
			}
			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();
			
			//不支持select * from .....这样的查询语句
			List students = session.createQuery("select * from Student").list();
			for (Iterator iter=students.iterator(); iter.hasNext();) {
				Student student = (Student)iter.next();
				System.out.println(student.getName());
			}
			session.getTransaction().commit();
		}catch(Exception e) {
			e.printStackTrace();
			session.getTransaction().rollback();
		}finally {
			HibernateUtils.closeSession(session);
		}
	}		
	
}