<?php

header('content-type:text/html;charset=utf-8');
error_reporting(E_ALL^E_NOTICE);
$mysqli?=?new?mysqli('localhost','root','199486','test');
if($mysqli->connect_errno){
????die('connect?error'.$mysqli->connect_error);
}
$mysqli->set_charset('utf8');
$username?=?$_POST['username'];
$password?=?$_POST['password'];
$age?=?$_POST['age'];
$act?=?$_GET['act'];
$id?=?$_GET['id'];
switch?($act){
????case?'addUser':
????????$sql?=?"INSERT?student(username,password,age)VALUES
????????('{$username}','{$password}','{$age}')";
????????$res=$mysqli->query($sql);
????????if($res){
????????????$insert_id?=?$mysqli->insert_id;
????????????echo?"<script>
????????????????????alert('添加成功，網站的第{$insert_id}');
????????????????????location.href='user_list.php';
????????????</script>";
????????????exit;
????????}else{
????????????echo?"<script>
????????????????????alert('添加失敗');
????????????????????location.href='addUser.php';
????????????</script>";
????????}
????????break;
????case?'delUser':
????????$sql?=?"DELETE?FROM?student?WHERE?id=".$id;
????????$res?=?$mysqli->query($sql);
????????if($res){
????????????$mes?=?"刪除成功";
????????}else{
????????????$mes?=?"刪除失敗";
????????}
????????$url?=?"user_list.php";
????????echo?"<script>
????????????????????alert('{$mes}');
????????????????????location.href='{$url}';
????????????</script>";
????????break;
}
?>

不明白你說的意思，給你看下我的