<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <%@page import="java.sql.DriverManager"%> <%@page import="java.sql.PreparedStatement"%> <%@page import="java.sql.Connection"%> <% request.setCharacterEncoding("UTF-8"); String id = request.getParameter("num"); String sql = "DELETE FROM `ydh`.`grade` WHERE (`num` = ?)"; Connection con = null; PreparedStatement ps = null; try{ con = DriverManager.getConnection("jdbc:mysql://localhost:3306/ydh?serverTimezone=UTC&useSSL=false&useUnicode=true&characterEncoding=utf8","root","123456"); ps = con.prepareStatement(sql); ps.setString(1, id); ps.executeUpdate(); out.print(""); ps.close(); con.close(); }catch(Exception e){ e.printStackTrace(); } %>