小编Nor*_*gey的帖子

这是我的数据库结构.关系很多很多.我想选出一些写过同一本书的作者.使用SQL,我做到了.我如何使用HQL？

   Query query = session.createSQLQuery("SELECT FirstName, LastName FROM authors, books, author_book as ab WHERE ab.authorID=authors.authorID AND ab.bookID = books.bookID AND ab.bookID = :id");
   query.setInteger("id", 1);
   List list = query.list();
   Iterator<Object[]> iter = list.iterator();
   while (iter.hasNext()) {
       Object[] obj = iter.next();
       System.out.println(obj[0] + " " + obj[1]);
    }

这个Servlet,我在彩色车上做GROUP BY.插入请求并在jsp中做广告,但它不会转换.

    Query query = session.createQuery("select count(carColor), carColor from Cars group by carColor order by carColor");
    List<Cars> list = query.list();
    Iterator iter = list.iterator();
    while (iter.hasNext()) {
        Object[] obj = (Object[]) iter.next();
        System.out.println(obj[0] + "  " + obj[1]);

    }

    request.setAttribute("list", list); 

    RequestDispatcher rd = request.getRequestDispatcher("test.jsp");
    rd.forward(request, response);

控制台:2白色10黑色5蓝色

JSP:[[Ljava.lang.Object; @ 1f3b536,[Ljava.lang.Object; @ fdffb1,]]