作业四

<%@ page import="java.sql.Connection" %>
<%@ page import="java.sql.Driver" %>
<%@ page import="java.sql.DriverManager" %>
<%@ page import="javax.swing.plaf.nimbus.State" %>
<%@ page import="java.sql.Statement" %>
<%@ page import="com.mysql.jdbc.PreparedStatement" %>

<%@ page contentType="text/html;charset=UTF-8" language="java" %>


<jsp:useBean id="user" class="com.name.user"></jsp:useBean>

<jsp:setProperty name="user" property="*"></jsp:setProperty>

<%
    //user对象实例化
    //userBean  user= new userBean();
    //给对象赋值
    //user.setUsername(request.getParameter("username"));
    //user.setPassword(request.getParameter("password"));
    //数据库操作
    //1.加载驱动程序
    Class.forName("com.mysql.jdbc.Driver");//报错，说明驱动包没有完成
    //建立数据库连接  18.3.22.1
    String url ="jdbc:mysql://127.0.0.1:3306/book";

    Connection connection = DriverManager.getConnection(url,"book","book");

    String sql = "insert into user(username,password,gender,age) values (?,?,?,?)";

    PreparedStatement temt = connection.prepareStatement(sql);
    temt.setString(1,request.getParameter("username"));
    temt.setString(2,request.getParameter("password"));
    temt.setString(3,request.getParameter("gender"));
    temt.setInt(4,request.getParameter("age"));
    ResultSet rs = temt.executeQuery();

<%@ page import="java.sql.Connection" %>
<%@ page import="java.sql.Driver" %>
<%@ page import="java.sql.DriverManager" %>
<%@ page import="javax.swing.plaf.nimbus.State" %>
<%@ page import="java.sql.Statement" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<jsp:useBean id="user" class="com.name.user">

</jsp:useBean>

<jsp:setProperty name="user" property="*"></jsp:setProperty>

<%
    Class.forName("com.mysql.jdbc.Driver");

    String url ="jdbc:mysql://127.0.0.1:3306/book?user=root&password=root";

    Connection connection = DriverManager.getConnection(url);

    String sql = "insert into user (username,password,gender,age) values ('"+user.getUsername()+"','"+user.getPassword()+"',1,23)";

    Statement stmt = connection.createStatement();

    int count = stmt.executeUpdate(sql);

    if(count == 0){
        out.print("注册失败");
    }else{
        out.print("注册成功");
    }

%>

<jsp:setProperty name="user" property="*"></jsp:setProperty>

<%
    //user对象实例化
    //userBean  user= new userBean();
    //给对象赋值
    //user.setUsername(request.getParameter("username"));
    //user.setPassword(request.getParameter("password"));
    //数据库操作
    //1.加载驱动程序
    Class.forName("com.mysql.jdbc.Driver");//报错，说明驱动包没有完成
    //建立数据库连接  18.3.22.1
    String url ="jdbc:mysql://127.0.0.1:3306/book?user=root&password=root";

    Connection connection = DriverManager.getConnection(url);

    //3创建Statement对象 执行sql语句  alt+enter  自动引入缺失的类
    Statement stmt = connection.createStatement();

    //删除
    String sql="delete from user where id = 4 ";

    int count = stmt.executeUpdate(sql);

    if(count == 0){
        out.print("删除失败");
    }else{
        out.print("删除成功");
    }

%>

本文地址：https://blog.csdn.net/weixin_45820586/article/details/108971924