数据库的连接，实现查找、删除、添加的语句
一、在教学资源库中下载 mysql 、NavicatforMySQL 然后进行安装 安装完成以后打开电脑管理-服务-启动sql
二、连接数据库 将mysql-connector-java-5.1.26-bin 放在bin 目录下 然后将DBHelper 复制在java的src 下
三、进行数据的插入，查询，删除的代码
首先在数据库里面建表
主要代码如下：
插入数据：
<%@page import="DBHelper.DBHelper"%>
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<!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=utf-8">
<title>Insert title here</title>
</head>
<body>
<%
String sql="insert into t_user(username,password) values ('zhangshan','123')";
DBHelper.ExecSql(sql);
%>
</body>
</html>
查询数据：
<%@page import="java.sql.ResultSet"%>
<%@page import="DBHelper.DBHelper"%>
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<!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=utf-8">
<title>Insert title here</title>
</head>
<body>
<%
String sql="select * from t_user where username=?";
ResultSet rs;
rs=DBHelper.getResultSet(sql, new Object[]{"zhangshan"});
while(rs.next()){
out.print(rs.getString("username")+",");
out.print(rs.getString("password")+"<br>");
}
%>
</body>
</html>
删除数据：
<%@page import="DBHelper.DBHelper"%>
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<!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=utf-8">
<title>Insert title here</title>
</head>
<body>
<%
String sql="delete from t_user where password='123'";
DBHelper.ExecSql(sql);
%>
</body>
</html>
