hibernate的hql02(08)

1. BaseDAO
   需求：
   按名字分页查询对应书籍信息

2. 原生sql
   hql实现不了的功能，可以考虑使用原生sql
   1、多表（5+）联查
   2、未配置映射文件中关系

3. 视图映射

   场景
   select * from 3表联查

create VIEW book_order
as
select b.book_name,o.order_no from t_hibernate_book b,t_hibernate_order o where 1=1

mysql也可以设置行号：
SELECT @rowno:=@rowno + 1 AS rowno,a.* FROM tableName a,(SELECT @rowno:=0) b

注:注意看有些不连贯的地方建议看前几篇博客
BookDao:

 	/** ------------------eight------------------*/   
	public List<Book> list1(Book book,PageBean pageBean){
		Session session = SessionFactoryUtil.getSession();
		Transaction transaction = session.beginTransaction();
		String hql="from Book where 1=1";
		if(StringUtils.isNotBlank(book.getBookName())){
			hql += "and bookName like :bookName";
		}
		Query query = session.createQuery(hql);
		if(StringUtils.isNotBlank(book.getBookName())){
			query.setParameter("bookName", "%"+book.getBookName()+"%");
		}
		if(pageBean != null && pageBean.isPagination()){
			query.setFirstResult(pageBean.getStartIndex());
			query.setMaxResults(pageBean.getRows());
		}
		List list = query.list();
		transaction.commit();
		session.close();
		return list;
	}
	
		public List<Book> list2(Book book,PageBean pageBean){
		Session session = SessionFactoryUtil.getSession();
		Transaction transaction = session.beginTransaction();
		Map<String, Object> map=new HashMap<String, Object>();
		String hql="from Book where 1=1";
		if(StringUtils.isNotBlank(book.getBookName())){
			hql += "and bookName like :bookName";
			map.put("bookName", book.getBookName());
		}
		
		List list = super.executeQuery(session, hql, pageBean, map);
		
		transaction.commit();
		session.close();
		return list;
	}
	
		public List<Object[]> list3(){
		Session session = SessionFactoryUtil.getSession();
		Transaction transaction = session.beginTransaction();
		Map<String, Object> map=new HashMap<String, Object>();
//		String hql="select b.bookName,o.orderNo from Book b,Order o where 1=1";
//		String sql="select b.book_name,o.order_no from t_hibernate_book b,t_hibernate_order o where 1=1";
		String sql ="select * from book_order"; //也可以hql语句 视图
		
//		List list = session.createQuery(sql).list();
		List list = session.createSQLQuery(sql).list(); //使用原生态sql
		transaction.commit();
		session.close();
		return list;
	}

PageBean:

package com.eight.dao;

import java.util.Map;

import javax.servlet.http.HttpServletRequest;

/**
 * 分页工具类
 *
 */
public class PageBean {

	private int page = 1;// 页码

	private int rows = 3;// 页大小

	private int total = 0;// 总记录数

	private boolean pagination = true;// 是否分页
	// 获取前台向后台提交的所有参数
	private Map<String, String[]> parameterMap;
	// 获取上一次访问后台的url
	private String url;

	/**
	 * 初始化pagebean
	 * 
	 * @param req
	 */
	public void setRequest(HttpServletRequest req) {
		this.setPage(req.getParameter("page"));
		this.setRows(req.getParameter("rows"));
		// 只有jsp页面上填写pagination=false才是不分页
		this.setPagination(!"fasle".equals(req.getParameter("pagination")));
		this.setParameterMap(req.getParameterMap());
		this.setUrl(req.getRequestURL().toString());
	}

	public int getMaxPage() {
		return this.total % this.rows == 0 ? this.total / this.rows : this.total / this.rows + 1;
	}

	public int nextPage() {
		return this.page < this.getMaxPage() ? this.page + 1 : this.getMaxPage();
	}

	public int previousPage() {
		return this.page > 1 ? this.page - 1 : 1;
	}

	public PageBean() {
		super();
	}

	public int getPage() {
		return page;
	}

	public void setPage(int page) {
		this.page = page;
	}

	public void setPage(String page) {
		this.page = StringUtils.isBlank(page) ? this.page : Integer.valueOf(page);
	}

	public int getRows() {
		return rows;
	}

	public void setRows(int rows) {
		this.rows = rows;
	}

	public void setRows(String rows) {
		this.rows = StringUtils.isBlank(rows) ? this.rows : Integer.valueOf(rows);
	}

	public int getTotal() {
		return total;
	}

	public void setTotal(int total) {
		this.total = total;
	}

	public void setTotal(String total) {
		this.total = Integer.parseInt(total);
	}

	public boolean isPagination() {
		return pagination;
	}

	public void setPagination(boolean pagination) {
		this.pagination = pagination;
	}

	public Map<String, String[]> getParameterMap() {
		return parameterMap;
	}

	public void setParameterMap(Map<String, String[]> parameterMap) {
		this.parameterMap = parameterMap;
	}

	public String getUrl() {
		return url;
	}

	public void setUrl(String url) {
		this.url = url;
	}

	/**
	 * 获得起始记录的下标
	 * 
	 * @return
	 */
	public int getStartIndex() {
		return (this.page - 1) * this.rows;
	}

	@Override
	public String toString() {
		return "PageBean [page=" + page + ", rows=" + rows + ", total=" + total + ", pagination=" + pagination
				+ ", parameterMap=" + parameterMap + ", url=" + url + "]";
	}

}

StringUtils:

   package com.zking.eight.dao;

public class StringUtils {
	// 私有的构造方法，保护此类不能在外部实例化
	private StringUtils() {
	}

	/**
	 * 如果字符串等于null或去空格后等于""，则返回true，否则返回false
	 * 
	 * @param s
	 * @return
	 */
	public static boolean isBlank(String s) {
		boolean b = false;
		if (null == s || s.trim().equals("")) {
			b = true;
		}
		return b;
	}
	
	/**
	 * 如果字符串不等于null或去空格后不等于""，则返回true，否则返回false
	 * 
	 * @param s
	 * @return
	 */
	public static boolean isNotBlank(String s) {
		return !isBlank(s);
	}

}

BaseDao:

package com.eight.dao;

import java.util.Collection;
import java.util.List;
import java.util.Map;

import org.hibernate.Session;
import org.hibernate.query.Query;



/**
 * 作用:
 * 	1、将赋值的操作交给basedao
 * 	2、分页
 * 		a、查询出符合条件的总记录数
 * 		b、查询符合条件的某一页记录
 * 
 * @author Administrator
 *
 */
public class BaseDao {
	/**
	 * 赋值的操作
	 * @param query 预定义对象
	 * @param map 	前台传递过来的参数
	 */
	private void setParameter(Query query,Map<String, Object> map){
//		query.setParameter("bookName", "%"+book.getBookName()+"%");
		if(map==null || map.size()==0){
			return;
		}
		
		Object value = null;
		for (Map.Entry<String, Object> entry : map.entrySet()) {
			value=entry.getValue();
			if(value instanceof Collection){
				query.setParameterList(entry.getKey(), (Collection) value);
			}else if(value instanceof Object[]){
				query.setParameterList(entry.getKey(), (Object[]) value);
			}else{
				query.setParameter(entry.getKey(), value);
			}
		}
	}
	
	/*
	 * sql = select * from t_hibernate_book where book_name like '%斗破%'
	 * countSql = select count(*) from ( select * from t_hibernate_book where book_name like '%斗破%') t 
	 * pageSql = sql+"limit ?,?";    hibernate中，这一步省略了
	 * 
	 *  hql = from Book where bokkName like '%斗破%'
	 *  hql = select bookName, price from Book where bokkName like '%斗破%'
	 *  
	 *  思路:
	 *  	截取from后的sql语句，前面拼接 select count(*)
	 *  From
	 *  from
	 *  fRom
	 *  frOm......
	 *  
	 *  转成大写
	 *  FROM
	 */
	
	/**
	 * 查询出符合条件的总记录数
	 * @param hql
	 * @return
	 */
	public String getCountHql(String hql){
		int index = hql.toUpperCase().indexOf("FROM");
		return "select count(*) "+ hql.substring(index);
	}
	
	public List executeQuery(Session session,String hql,PageBean pageBean,Map<String, Object> map){
		if(pageBean != null && pageBean.isPagination()){
			// select count(*) Book where bokkName like '%斗破%'
			String countHql = getCountHql(hql);
			Query countQuery = session.createQuery(countHql);
			this.setParameter(countQuery, map);
			//pagebean设置总记录数，最后用于分页
			String total = countQuery.getSingleResult().toString();
			pageBean.setTotal(total);
			
			//查询展示的数据
			Query pageQuery = session.createQuery(hql);
			this.setParameter(pageQuery, map);
			pageQuery.setFirstResult(pageBean.getStartIndex());
			pageQuery.setMaxResults(pageBean.getRows());
			
			return pageQuery.list();
		}else{//不分页
			Query query = session.createQuery(hql);
			this.setParameter(query, map);
			return query.list();
		}
	}
}

测试Junit：
package com.eight.test;

import java.util.Arrays;
import java.util.List;

import org.junit.Test;

import com.eight.dao.PageBean;
import com.five.dao.BookDao;
import com.five.entity.Book;

public class TestQuery {
	private BookDao bookDao = new BookDao();

	@Test
	public void testList1() {
		PageBean pageBean = new PageBean();
		// pageBean.setPage(2);
		Book book = new Book();
		book.setBookName("斗破苍穹");
		List<Book> list1 = this.bookDao.list1(book, pageBean);
		for (Book b : list1) {
			System.out.println(b);
		}
	}

	@Test
	public void testList2() {
		PageBean pageBean = new PageBean();
		// pageBean.setPage(2);
		Book book = new Book();
		book.setBookName("斗破苍穹");
		List<Book> list1 = this.bookDao.list2(book, pageBean);
		for (Book b : list1) {
			System.out.println(b);
		}
	}

	@Test
	public void testList3() {
		PageBean pageBean = new PageBean();
		// pageBean.setPage(2);
		Book book = new Book();
//		book.setBookName("斗破苍穹");
		List<Object[]> list1 = this.bookDao.list3();
		for (Object[] b : list1) {
			System.out.println(Arrays.toString(b));
		}
	}
}