CentOS7使用yum安装MySQL8.x
# yum localinstall https://repo.mysql.com//mysql80-community-release-el7-1.noarch.rpm
# yum install mysql-community-server.x86_64
启动 mysql:
# systemctl start mysqld.service
查看mysql 服务的运行状态
# systemctl status mysqld.service
mysqld.service - MySQL Server
Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
Active: active (running) since Tue 2019-02-26 18:14:13 PST; 1h 10min ago
Docs: man:mysqld(8)
http://dev.mysql.com/doc/refman/en/using-systemd.html
Process: 22524 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
Main PID: 22670 (mysqld)
Status: "SERVER_OPERATING"
CGroup: /system.slice/mysqld.service
└─22670 /usr/sbin/mysqld
Feb 26 18:14:00 localhost.localdomain systemd[1]: Starting MySQL Server...
Feb 26 18:14:13 localhost.localdomain systemd[1]: Started MySQL Server.
查看密码
[root@localhost run]# grep 'password' /var/log/mysqld.log
2019-02-27T02:14:06.098913Z 5 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: :pk;Sgz/U1(6
登陆mysql
$ mysql -uroot -p":pk;Sgz/U1(6"
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 13
Server version: 8.0.15
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>
修改密码（由于默认的密码策略等为中级，一般的密码不能通过，所以先随便一个复杂度较高的密码，之后变更。）
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'qwer1234';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
mysql> show variables like 'validate_password%';
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'z?guwrBhH7p>';
Query OK, 0 rows affected (0.03 sec)
mysql> show variables like 'validate_password%';
+--------------------------------------+--------+
| Variable_name | Value |
+--------------------------------------+--------+
| validate_password.check_user_name | ON |
| validate_password.dictionary_file | |
| validate_password.length | 8 |
| validate_password.mixed_case_count | 1 |
| validate_password.number_count | 1 |
| validate_password.policy | MEDIUM |
| validate_password.special_char_count | 1 |
+--------------------------------------+--------+
7 rows in set (0.01 sec)
修改密码策略（降低要求，这样就可以随意设置密码了）
mysql> set global validate_password.policy=0;
Query OK, 0 rows affected (0.00 sec)
mysql> set global validate_password.length=1;
Query OK, 0 rows affected (0.00 sec)
mysql> show variables like 'validate_password%';
+--------------------------------------+-------+
| Variable_name | Value |
+--------------------------------------+-------+
| validate_password.check_user_name | ON |
| validate_password.dictionary_file | |
| validate_password.length | 4 |
| validate_password.mixed_case_count | 1 |
| validate_password.number_count | 1 |
| validate_password.policy | LOW |
| validate_password.special_char_count | 1 |
+--------------------------------------+-------+
7 rows in set (0.58 sec)
再次修改密码
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'qwer1234';
Query OK, 0 rows affected (0.03 sec)
可视化工具的登录授权：(如果授权不成功，请查看防火墙) mysql8 与 mysql5 授权语句不同。
操作完成上面的，现在还不能用可视化的客户端进行连接，需要我们进行授权：
mysql> use mysql;
mysql> select host,user from user;
+-----------+------------------+
| host | user |
+-----------+------------------+
| localhost | mysql.infoschema |
| localhost | mysql.session |
| localhost | mysql.sys |
| localhost | root |
+-----------+------------------+
4 rows in set (0.00 sec)
mysql> create user 'root'@'%' identified by 'qwer1234';
Query OK, 0 rows affected (0.04 sec)
mysql> select host,user from user;
+-----------+------------------+
| host | user |
+-----------+------------------+
| % | root |
| localhost | mysql.infoschema |
| localhost | mysql.session |
| localhost | mysql.sys |
| localhost | root |
+-----------+------------------+
5 rows in set (0.00 sec)
mysql> grant all privileges on *.* to 'root'@'%' ;
Query OK, 0 rows affected (0.01 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
mysql8密码加密方式的变更：
之前默认是mysql_native_password，现在改为caching_sha2_password。很多连接工具，像nivacat12，仍然使用默认的mysql_native_password，所以在连接的时候回报错：
1251：Client does not support authentication protocol requested by server; consider upgrading
MySQL client
此时需要将mysql.user表中的plugin字段修改下：
mysql> select host, user, plugin from user;
+-----------+------------------+-----------------------+
| host | user | plugin |
+-----------+------------------+-----------------------+
| % | root | caching_sha2_password |
| localhost | mysql.infoschema | caching_sha2_password |
| localhost | mysql.session | caching_sha2_password |
| localhost | mysql.sys | caching_sha2_password |
| localhost | root | caching_sha2_password |
+-----------+------------------+-----------------------+
5 rows in set (0.00 sec)
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'qwer1234' PASSWORD EXPIRE NEVER;
Query OK, 0 rows affected (0.01 sec)
mysql> ALTER USER 'root'@'%' IDENTIFIED WITH mysql_native_password BY 'qwer1234';
Query OK, 0 rows affected (0.04 sec)
mysql> select host, user, plugin from user;
+-----------+------------------+-----------------------+
| host | user | plugin |
+-----------+------------------+-----------------------+
| % | root | mysql_native_password |
| localhost | mysql.infoschema | caching_sha2_password |
| localhost | mysql.session | caching_sha2_password |
| localhost | mysql.sys | caching_sha2_password |
| localhost | root | mysql_native_password |
+-----------+------------------+-----------------------+
5 rows in set (0.00 sec)
关闭防火墙并禁止启动
[root@localhost code]# systemctl stop firewalld.service
[root@localhost code]# systemctl disable firewalld.service
Removed symlink /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.
Removed symlink /etc/systemd/system/basic.target.wants/firewalld.service.
参考：
https://www.cnblogs.com/brianzhu/p/8575243.html
https://blog.csdn.net/xinpengfei521/article/details/80403965