<%@page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@page import="java.sql.*"%>
<html>
<head>
<title>图书管理系统</title>
</head>
<body bgcolor="#CCCCFF" align=center>
<%
String DRIVER = "org.gjt.mm.mysql.Driver";
String DURL = "jdbc:mysql://localhost:3306/jsptest";
String DUSER = "root";
String DPASS = "594daidai";
String sqlstr_table="show tables";
// String sqlstr_booknumber="select booknumber from "+tablename;//这里的test我想用上一个框中选择的tablename来动态的选择，但是报错只能用下面的固定形式
String sqlstr_booknumber="select booknumber from test";
Class.forName(DRIVER);
Connection conn = DriverManager.getConnection(DURL,DUSER,DPASS);
Statement st_table=conn.createStatement();
Statement st_booknumber=conn.createStatement();
ResultSet rs_table=st_table.executeQuery(sqlstr_table);
ResultSet rs_booknumber=st_booknumber.executeQuery(sqlstr_booknumber);
%>
<form action="dodeletedata.jsp">
<table align=center border=1 cellpadding="0" cellspacing="0" color="#003399">
<div id="myDiv">
<tr>
<td>输入要删除的表名：
<select name="tablename" style="width:138px;"list="lis_table" onchange="showUser(this.value)">
<datalist id="lis_table">
<%while(rs_table.next()){%>
<option value="<%=rs_table.getString(1)%>"><%=rs_table.getString(1)%></option>
<%}%>
</datalist>
</select>
</td>
</tr>
</div>
<tr>
<td>输入要删除的编号：
<select name="booknumber" style="width:138px;"list="lis_booknumber">
<datalist id="lis_booknumber">
<%while(rs_booknumber.next()){%>
<option value="<%=rs_booknumber.getString(1)%>"><%=rs_booknumber.getString(1)%></option>
<%}%>
</datalist>
</select>
</td>
</tr>
<tr><td><input type=submit value="确定">
<input type=reset value="取消"></td></tr>
</table>
</form>
<br><a href="index.jsp">返回首页</a>
<%
rs_booknumber.close();
rs_table.close();
st_booknumber.close();
st_table.close();
conn.close();
%>
</body>
</html>
如图所示，我想下拉第一个框动态显示第二个框的编号名如何实现
