一.创建一个数据库db_idlist执行SQL代码
DROP TABLE IF EXISTS `tb_idlist`; CREATE TABLE `tb_idlist` ( `id` int(11) NOT NULL AUTO_INCREMENT, `content` varchar(20) DEFAULT NULL, PRIMARY KEY (`Id`) ) ENGINE=MyISAM AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;
二.新建index.php
<?php $conn=mysqli_connect("127.0.0.1","root","123456","db_idlist") or die("数据库服务器连接错误".mysqli_error($conn)); mysqli_select_db($conn,"db_idlist") or die("数据库访问错误".mysqli_error($conn)); mysqli_query($conn,"set names utf-8"); $query = mysqli_query($conn, ‘select * from tb_idlist;‘); if (!$query) { exit(‘<h1>查询数据失败</h1>‘); } while ($item = mysqli_fetch_assoc($query)); ?> <!DOCTYPE html> <html> <head> <title>ID重新排序</title> </head> <body> <table align="center"> <h1><a href="listid.php">排序</a></h1> <tr> <th scope="row"><?php echo $item[‘id‘]; ?></th> <td><?php echo $item[‘content‘]; ?></td></tr> </table> </body> </html>
三.创建listid.php
<?php $conn=mysqli_connect("127.0.0.1","root","123456","db_idlist") or die("数据库服务器连接错误".mysqli_error($conn)); mysqli_select_db($conn,"db_idlist") or die("数据库访问错误".mysqli_error($conn)); mysqli_query($conn,"set names utf-8"); $sql = "alter table tb_idlist drop column id;";//删除原有表中的id字段 $query = mysqli_query($conn,$sql); echo mysqli_error($conn); if(!$query){ exit(‘<h1>查询数据失败</h1>‘); } $sqll = "alter table tb_idlist add id mediumint(8) not null primary key auto_increment first;";//重新设置id主键并自动从1开始自增 $query = mysqli_query($conn,$sqll); echo mysqli_error($conn); if(!$query){ exit(‘<h1>查询数据失败</h1>‘); } header(‘Location: index.php‘); ?>
原文：https://www.cnblogs.com/wlei5206/p/12755478.html