管理员操作2
接下来要实现管理员更新图书信息的功能，原理与添加图书信息类似。
首先要求输入需要修改的图书名称，然后从数据库中检索出该图书的信息进行修改，修改完成后再写进数据库。
updatebookinfo.jsp
<%@ page language="java" contentType="text/html; charset=gb2312"
pageEncoding="gb2312"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>修改图书</title>
</head>
<body background=C:\Users\Administrator\Desktop\image\2.jpg>
<form action="updatebook.jsp" method="post" name="form">
请输入图书书名：<input type="text" name="t1"><br> <br>
<input type="submit" name="button" value="提交"><br>
</form>
</body>
</html>
输出数据库中图书的信息并进行修改updatebook.jsp
<%@ page language="java" contentType="text/html; charset=gb2312" import="java.sql.*"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<% request.setCharacterEncoding("gb2312");%>
<%@page import="java.sql.*,java.io.*,java.lang.*"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>修改图书信息</title>
</head>
<body>
<%
String m=request.getParameter("t1");
String DRIVER = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
String USER = "sa";
String PASSWORD = "123456";
String URL = "jdbc:sqlserver://localhost:1433;databaseName=book";
Class.forName(DRIVER);
Connection conn=DriverManager.getConnection(URL, USER, PASSWORD);
Statement stmt=conn.createStatement();
String sql="SELECT * FROM bookinfo where bookName='"+m+"' ";
ResultSet rs=stmt.executeQuery(sql);
%>
<form action="updatebook1.jsp?id=<%=m %>" method="post" name=f1>
<table border=1>
<tr>
<td>书名</td>
<td>简介</td>
<td>库存</td>
<td>分类</td>
<td>售价</td>
</tr>
<% while(rs.next()){
String n=rs.getString(2);
String intro=rs.getString(3);
String invent=rs.getString(4);
String c=rs.getString(6);
int s=rs.getInt(7);
%>
<tr>
<td><input type="text" name="t1" value=<%=n%>></td>
<td><input type="text" name="t2" value=<%=intro %>> </td>
<td> <input type="text" name="t3" value=<%=invent %>></td>
<td> <input type="text" name="t4" value=<%=c%>></td>
<td> <input type="text" name="t5" value=<%=s %>></td>
</tr>
<% } %>
</table>
<input type="submit" value="提交">
</form>
</body>
</html>
对数据库更新updatebook1.jsp
<%@ page language="java" contentType="text/html; charset=gb2312"
pageEncoding="gb2312"%>
<%@page import="java.sql.*,java.io.*,java.lang.*"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>更新图书</title>
</head>
<body>
<%
String t=request.getParameter("id");
String t1=request.getParameter("t1");
String t2=request.getParameter("t2");
String t3=request.getParameter("t3");
String t4=request.getParameter("t4");
int t5=Integer.parseInt(request.getParameter("t5"));
String DRIVER = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
String USER = "sa";
String PASSWORD = "123456";
String URL = "jdbc:sqlserver://localhost:1433;databaseName=book";
Class.forName(DRIVER);
Connection conn=DriverManager.getConnection(URL, USER, PASSWORD);
Statement stmt=conn.createStatement();
String sql="Update bookinfo set bookName='"+t1+"',intro='"+t2+"',inventory='"+t3+"',classify='"+t4+"',sell='"+t5+"' where bookName='"+t+"'";
stmt.executeUpdate(sql);
out.print("更新成功！");
%>
</body>
</html>
