mysql8.0新增用户及密码加密规则修改

MySQL8.0已经发布GA版，当前最新GA版本为8.0.12。虽然相对于之前版本，MySQL8.0没有加入新元素，但是，经过代码重构，MySQL8.0的优化器更加强大，同时也有一些新特性，如支持索引隐藏等。

但是，MySQL新版本中也有很多与先前版本不一样的地方，比如在用户创建上就有很多变化。

1. 用户创建

创建用户的操作已经不支持grant的同时创建用户的方式，需先创建用户再进行授权

mysql> grant all on *.* to 'admin'@'%' identified by 'admin123';
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'identified by 'admin123'' at line 1
mysql> create user  'admin'@'%' identified by 'admin123';
Query OK, 0 rows affected (0.06 sec)

mysql> grant all on *.* to 'admin'@'%' ;
Query OK, 0 rows affected (0.04 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

2. 用户登录1

当用户密码含有字母或数字外的特殊符号登录时，原先使用双引号或单引号都可以登录，但在mysql8.0登录时遇到问题，如下

[root@gjc18 lib]# /usr/local/mysql8.0/bin/mysql -uroot -p"root!@#123" --socket=/data/mysql/mysql3310/tmp/mysql3310.sock
-bash: !@#123": event not found
[root@gjc18 lib]# /usr/local/mysql8.0/bin/mysql -uroot -p'root!@#123' --socket=/data/mysql/mysql3310/tmp/mysql3310.sock
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 22
Server version: 8.0.12 MySQL Community Server - GPL

3.低版本客户端登录异常

错误号码 2058：Plugin caching_sha2_password could not be loaded

出现这个原因是mysql8.0 之前的版本中加密规则是mysql_native_password,而在mysql8之后,加密规则是caching_sha2_password, 解决此问题方法有两种,一种是升级客户端驱动,一种是把mysql用户登录密码加密规则还原成mysql_native_password。

如果修改用户密码加密规则可使用如下方式：

1）. 修改加密方式：

-- 修改密码为用不过期
mysql> ALTER USER 'root'@'%' IDENTIFIED BY 'password' PASSWORD EXPIRE NEVER; 
Query OK, 0 rows affected (0.02 sec)

-- 修改密码并指定加密规则为mysql_native_password
mysql> ALTER USER 'root'@'%' IDENTIFIED WITH mysql_native_password BY '123456';
Query OK, 0 rows affected (0.01 sec)

-- 刷新权限
mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)

mysql>

修改完毕后再次登录即可成功

2）.使用高版本客户端

linux低版本客户端登录时也会出现此情况，因此需使用高版本的客户端

[root@gjc18 lib]# mysql -uroot -p'123456' --socket=/data/mysql/mysql3310/tmp/mysql3310.sock
mysql: [Warning] Using a password on the command line interface can be insecure.
ERROR 2059 (HY000): Authentication plugin 'caching_sha2_password' cannot be loaded: /usr/local/mysql/lib/plugin/caching_sha2_password.so: cannot open shared object file: No such file or directory
[root@gjc18 lib]# /usr/local/mysql8.0/bin/mysql -uroot -p'123456' --socket=/data/mysql/mysql3310/tmp/mysql3310.sock
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 26
Server version: 8.0.12 MySQL Community Server - GPL

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