java web 网页问题

<table border="1" align="center" width="400"> <% Connection conn = ConnectionDB.getConnectionDB(); String sql = " select * from diningcar,food,users where diningcar.foodId=food.id and diningcar.userName=users.userName collate chinese_prc_ci_as"; PreparedStatement pstmt = conn.prepareStatement(sql); pstmt.executeQuery(); ResultSet rs = pstmt.executeQuery(); while(rs.next()){ %> <tr> <td colspan="2">用户名:<%=rs.getString("userName")%></td> </tr> <% while (rs.next()) { %> <tr> <td>菜名:<%=rs.getString("foodName")%></td> <td>单价:<%=rs.getString("price")%></td> </tr> <% } } %> </table>我想的是一个用户名对应他所点的所有菜，但是这样写，只能显示出他选的1个菜怎么改啊