yum安装指定版本的mysql

yum安装指定版本的mysql
https://www.51anidea.com/forum.php?mod=viewthread&tid=513
(出处: Linux教程网)
1、环境
CentOS 7.4
2、安装方法
一、下载mysql源
#wget http://repo.mysql.com/mysql80-community-release-el7.rpm
（若是要安装其余版本的mysql，能够去 http://repo.mysql.com/ 下面查找其余版本的mysql）
二、安装mysql源
#rpm -ivh mysql80-community-release-el7.rpm
三、安装mysql
#yum -y install mysql-server
四、更改权限
#chown mysql:mysql -R /var/lib/mysql
五、初始化
#mysqld --initialize
六、启动mysql
#systemctl start mysqld

（1）若是没法启动（也许是与以前的mysql版本不兼容）
查看日志
#cat /var/log/mysqld.log
2019-09-14T06:28:57.838520Z 0 [ERROR] [MY-010457] [Server] --initialize specified but the data directory has files in it. Aborting.

2019-09-14t06:28:57.838520Z 0[错误][my-010457][服务器]--已指定初始化，但date目录中有文件。停止。

原来是date目录中有文件。

（2）解决办法
找到配置文件，修改date目录
vi /etc/my.cnf

将原目录datedir=/var/lib/mysql修改成datedir=/var/lib/mysql1
再新建目录
#mkdir datedir=/var/lib/mysql1

或者直接删除/var/lib/mysql的文件
#rm -r /var/lib/mysql

七、查看mysql的日志，找到mysql的初始密码
#cat /var/log/mysqld.log
找到如下信息：
2019-03-05T00:26:37.417710Z 5 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: :18dKSAditnu

故mysql的初始密码是 18dKSAditnu

八、更改mysql的密码（不更改的话，没法使用mysql）
#mysqladmin -u root -p"18dKSAditnu" password "新密码"
执行后会出现如下提示信息：
mysqladmin: [Warning] Using a password on the command line interface can be insecure.
Warning: Since password will be sent to server in plain text, use ssl connection to ensure password safety.

以上只是警告信息，没有影响

九、登陆mysql
#mysql -u root -p

[root@localhost ~]# mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 14
Server version: 8.0.15 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> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
+--------------------+
4 rows in set (0.01 sec)

至此，mysql8.0安装完毕。