jsp写数据,为什么数据库里没有数据
<%@ page language="java" import="java.sql.*"%>
<%@ page contentType="text/html;charset=GB18030"%>
<%@ page import="java.util.*" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html;charset=gb2312">
</head>
<body>
<%
request.setCharacterEncoding("GB18030");
String id=request.getParameter("id");
String username=request.getParameter("name");
String password=request.getParameter("nametwo");
try{
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver").newInstance(); ;
Connection conn=DriverManager.getConnection("jdbc:sqlserver://localhost:1433;databaseName=TEST1","sa","321654");
Statement stmt=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
String sql="insert into userTable(id,username,password) values("+id+","+username+","+password+")";
String selectquery="select * from userTable where username='"+username+"'";
stmt= conn.createStatement();
ResultSet rs=stmt.executeQuery(selectquery);
if(rs.next()){
response.sendRedirect("register.jsp");
return;}
else{
stmt.executeUpdate(sql);}
rs.close();
stmt.close();
conn.close();
}catch(SQLException ex)
{
ex.printStackTrace();
response.sendRedirect("head.jsp");}
%>
</body>
</html>