php连接MySQL8.0版本数据库密码验证失败解决方法（笔记） The server requested ... to the client [caching_sha2_password]...

php连接MySQL8.0版本数据库密码验证失败解决方法

• 因为MySQL8以后版本的密码加密方式与MySQL以前版本不一样！MySQL8是caching_sha2_password加密,MySQL以前版本是mysql_native_password加密，所以本人使用phpmysqli_connect连接数据库失败！（使用cmd命令mysql -u root -p连接成功，使用可视化工具Navicat Premium连接成功！）
• 失败效果及解决方法如下。

cmd连接成功

E:\StudyFile\mysql\mysql-8.0.16-winx64\bin>mysql -u root -p
Enter password: ******
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 24
Server version: 8.0.16 MySQL Community Server - GPL

Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>

Navicat Premium连接成功

php连接失败

php代码

<?php

$connection = mysqli_connect('127.0.0.1', 'root', '123456', 'demo2');

if (!$connection) {
  // 连接数据库失败
  exit('<h1>连接数据库失败</h1>');
}

$query = mysqli_query($connection, 'select * from users;');


while ($row = mysqli_fetch_assoc($query)) {
  var_dump($row);
}

连接失败警告

Warning: mysqli_connect(): The server requested authentication method unknown to the client [caching_sha2_password] in F:\code\01-mysql.php on line 13

Warning: mysqli_connect(): (HY000/2054): The server requested authentication method unknown to the client in F:\code\01-mysql.php on line 13

解决方法

• 修改加密方式
• 使用新版本客户端（不说明）

使用cmd 修改加密方式

在进入mysql编辑后使用命令：mysql> ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'password';
把新版本加密方式caching_sha2_password改为旧加密方式mysql_native_password

mysql> ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '1
23456';
Query OK, 0 rows affected (0.12 sec)

更新 命令：flush privileges;

mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)

修改完成！可以读取数据库信息了

array(5) { ["id"]=> string(1) "1" ["title"]=> string(6) "实例" ["name"]=> string(7) " 小明" ["age"]=> string(2) "15" ["gender"]=> string(1) "0" }