对于 CREATE TABLE 或 DROP TABLE 等不操作行的语句,executeUpdate 的返回值总为零。
pstmt.executeUpdate();
关闭链接
pstmt.close();
conn.close();
页面跳转
response.sendRedirect("list.jsp");
添加成功后,跳转回“学生信息列表”界面。
完整的add_success.jsp代码
<%@ page import="java.sql.Connection" %><%@ page import="java.sql.DriverManager" %><%@ page import="java.sql.PreparedStatement" %><%--
Created by IntelliJ IDEA.
User: 11202
Date: 2024/4/3
Time: 13:47
To change this template use File | Settings | File Templates.
--%><%@ page contentType="text/html;charset=UTF-8" language="java" %><%
//接收参数
String sname = request.getParameter("sname");
String money = request.getParameter("money");
String birthday = request.getParameter("birthday");
//链接数据库
Class.forName("com.mysql.cj.jdbc.Driver");
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mywork", "root", "123456");
PreparedStatement pstmt = conn.prepareStatement("insert into student(sname, money, birthday) values(?,?,?)");
pstmt.setObject(1, sname);
pstmt.setObject(2, money);
pstmt.setObject(3, birthday);
pstmt.executeUpdate();
pstmt.close();
conn.close();
//页面跳转
response.sendRedirect("list.jsp");
%>
三、修改信息页面upd.jsp
点击“修改”按钮,跳转到学生信息页面,将其中的旧数据修改为新数据,之后点击提交,即可修改信息。
因此,它的实现思路是,在add.jsp基础上,将各个输入框的信息要能够“显示出旧数据”。
此外,它的SQL语句也有所不同,它是update语句,而不是insert语句了。
>" >修改
注意,我们通过请求href,已经获取到了当前点击学生的sid,之后作处理即可。
页面主要内容
head内容
修改学生信息
body内容
四、学生信息修改操作upd_success.jsp
同理,把html相关代码全部删去,只负责写Java代码,负责前端input传递过来的数据与数据库进行交互。
接收参数
<%
//接收参数
String sid = request.getParameter("sid");
String sname = request.getParameter("sname");
String money = request.getParameter("money");
String birthday = request.getParameter("birthday");
%>
链接数据库
Class.forName("com.mysql.cj.jdbc.Driver");
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mywork", "root", "123456");
执行SQL语句
PreparedStatement pstmt = conn.prepareStatement("update student set sname=?, money=?, birthday=? where sid=?");
pstmt.setObject(1, sname);
pstmt.setObject(2, money);
pstmt.setObject(3, birthday);
pstmt.setObject(4, sid);
pstmt.executeUpdate();
关闭链接
pstmt.close();
conn.close();
页面跳转
response.sendRedirect("list.jsp")
完整upd_success.jsp代码
<%@ page import="java.sql.DriverManager" %><%@ page import="java.sql.Connection" %><%@ page import="java.sql.PreparedStatement" %><%--
Created by IntelliJ IDEA.
User: 11202
Date: 2024/4/3
Time: 15:29
To change this template use File | Settings | File Templates.
--%><%@ page contentType="text/html;charset=UTF-8" language="java" %><%
//传递参数
String sid = request.getParameter("sid");
String sname = request.getParameter("sname");
String money = request.getParameter("money");
String birthday = request.getParameter("birthday");
//建立链接
Class.forName("com.mysql.cj.jdbc.Driver");
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mywork", "root", "123456");
PreparedStatement pstmt = conn.prepareStatement("update student set sname=?, money=?, birthday=? where sid=?");
pstmt.setObject(1, sname);
pstmt.setObject(2, money);
pstmt.setObject(3, birthday);
pstmt.setObject(4, sid);
pstmt.executeUpdate();
//关闭链接
pstmt.close();
conn.close();
//页面跳转
response.sendRedirect("list.jsp");
%>
五、学生信息删除操作del_success.jsp
由于删除的过程是,在list.jsp中,点击“删除按钮”,对应记录消失。因此,不需要设置额外的界面,而只需实现这一功能操作即可。
因此,不需要del.jsp,只需del_success.jsp。
同理,将html相关代码均删除,只写Java代码。
" >删除
获取参数
String sid = request.getParameter("sid");
链接数据库
Class.forName("com.mysql.cj.jdbc.Driver");
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mywork", "root", "123456");
SQL语句执行
PreparedStatement pstmt = conn.prepareStatement("delete from student where sid=?");
pstmt.setObject(1, sid);
pstmt.executeUpdate();
关闭链接
pstmt.close();
conn.close();
页面跳转
response.sendRedirect("list.jsp");
完整del_success.jsp代码
<%@ page import="java.sql.DriverManager" %><%@ page import="java.sql.Connection" %><%@ page import="java.sql.PreparedStatement" %><%--
Created by IntelliJ IDEA.
User: 11202
Date: 2024/4/3
Time: 15:39
To change this template use File | Settings | File Templates.
--%><%@ page contentType="text/html;charset=UTF-8" language="java" %><%
//传递参数
String sid = request.getParameter("sid");
String sname = request.getParameter("sname");
String money = request.getParameter("money");
String birthday = request.getParameter("birthday");
//建立链接
Class.forName("com.mysql.cj.jdbc.Driver");
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mywork", "root", "123456");
//SQL语句
PreparedStatement pstmt = conn.prepareStatement("delete from student where sid=?");
pstmt.setObject(1, sid);
pstmt.executeUpdate();
//关闭链接
pstmt.close();
conn.close();
//页面跳转
response.sendRedirect("list.jsp");
%>