一、mysql 5.7和8.0安装

一、MySql安装

1.1、安装前的检查

1.1.1、卸载已安装的mysql

rpm -qa | grep -i mysql

1.1.2.、确认mysql服务已关闭，如果没关闭，则关闭服务

service mysqld status;
service mysql stop;  

 1.1.3、卸载已安装的mysql软件包

rpm -e --nodeps akonadi-mysql-1.9.2-4.el7.x86_64
rpm -e --nodeps qt-mysql-4.8.7-8.el7.x86_64
rpm -e --nodeps perl-DBD-MySQL-4.023-6.el7.x86_64
rpm -e --nodeps perl-DBD-MySQL-4.023-6.el7.x86_64

1.1.4、删除旧版本mysql文件和目录

查询mysql旧文件和目录

find / -name mysql

删除mysql旧文件和目录

rm -rf /var/lib/pcp/config/pmlogconf/mysql
rm -rf /etc/selinux/targeted/active/modules/100/mysql
rm -rf /var/lib/mysql
rm -rf /usr/bin/mysql
rm -rf /usr/lib64/mysql
rm -rf /usr/share/mysql

1.1.5、删除配置文件

rm -rf /etc/my.cnf

1.1.6、删除 mysql 用户以及用户组

id mysql
 
userdel mysql 

1.1.7、 卸载系统默认安装的 Mariadb

rpm -qa | grep -i mariadb

rpm -e --nodeps mariadb-5.5.65-1.el7.x86_64
rpm -e --nodeps mariadb-server-5.5.65-1.el7.x86_64
rpm -e --nodeps mariadb-libs-5.5.65-1.el7.x86_64
确认mariadb卸载成功
rpm qa | grep -i mariadb

 二、安装MySQL

        在大多数情况下，需要安装 mysql-community-server、mysql-community-client、mysql-community-libs、 mysql-community-common 以及 mysql-community-libs-compat这五个安装包， 才能获得一个标准功能的 MySQL。 到官网上下载对应的安装包：

mysql-community-client-5.7.31-1.el7.x86_64.rpm

mysql-community-common-5.7.31-1.el7.x86_64.rpm

mysql-community-libs-5.7.31-1.el7.x86_64.rpm

mysql-community-libs-compat-5.7.31-1.el7.x86_64.rpm

mysql-community-server-5.7.31-1.el7.x86_64.rpm

 1、上传rpm安装包到/home目录下

2、为安装包赋权限

chmod 755 mysql*

3.、依次执行如下命令， 注意命令执行的顺序，如下所示

rpm -ivh mysql-community-common-5.7.31-1.el7.x86_64.rpm --nodeps --force
rpm -ivh mysql-community-libs-5.7.31-1.el7.x86_64.rpm --nodeps --force
rpm -ivh mysql-community-libs-compat-5.7.31-1.el7.x86_64.rpm --nodeps --force
rpm -ivh mysql-community-client-5.7.31-1.el7.x86_64.rpm --nodeps --force
rpm -ivh mysql-community-server-5.7.31-1.el7.x86_64.rpm --nodeps --force

4.、启动 mysql 服务， 并获取数据库超级用户 root 的密码

service mysqld start
service mysqld status
service mysqld stop
查看root用户初始密码
grep 'temporary password' /var/log/mysqld.log

 5.、登录数据库并修改密码 

mysql -uroot -p
修改密码
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
(root@localhost) [(none)]> ALTER USER 'root'@'localhost' IDENTIFIED BY 'Wzb@132513';
密码简单了会报错

查看密码安全策略
show variables like 'validate_password%'; 
降低密码复杂度限制：
set global validate_password_policy=0;
降低密码长度限制：
set global validate_password_length=4;

----------mysql 8 使用以下sql

在mysql8.0.23  需要先修改密码，才能改密码策略 
降低密码复杂度限制：
set global validate_password.policy=0;
降低密码长度限制：
set global validate_password.length=4;
在修改密码
mysql> flush privileges;
配置 root 用户远程登陆权限
mysql> grant all privileges on *.* to 'root'@'%' identified by '123456' with grant option; 
mysql>grant all privileges on *.* to 'hangxin'@'%' identified by 'hangxin_pwd' with grant option;
 
查询密码有效期
(root@localhost) [(none)]> SELECT password_last_changed, password_lifetime FROM mysql.user WHERE user = 'root';
+-----------------------+-------------------+
| password_last_changed | password_lifetime |
+-----------------------+-------------------+
| 2023-12-22 11:03:56   |              NULL |
+-----------------------+-------------------+
password_last_changed 字段表示密码最后更改的时间，password_lifetime 字段表示密码的生命周期（以天为单位）

--mysql 8 以后  先创建用户 在授权授权

mysql>CREATE USER 'root'@'%'IDENTIFIED BY '123456';
mysql>GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' WITH GRANT OPTION;
mysql> flush privileges;
远程访问需要修改权限
select user,host,plugin from user;    查看密码加密规则
ALTER USER 'root'@'%' IDENTIFIED BY '123456' PASSWORD EXPIRE NEVER;
ALTER USER 'root'@'%' IDENTIFIED WITH mysql_native_password BY '123456';
FLUSH PRIVILEGES; 

三、MySQL相关文件默认存放路径

 四、mysql 8.0安装

        按照上方1.1的步骤先检查服务器默认安装的mysql ,删除相关文件

在/usr/local/创建mysql文件夹
[root@bogon local]# mkdir mysql
[root@bogon local]# cd mysql
#下载rpm安装包
[root@bogon mysql]# wget https://dev.mysql.com/get/Downloads/MySQL-8.0/mysql-8.0.16-2.el7.x86_64.rpm-bundle.tar
#解压
[root@bogon mysql]# tar -xvf mysql-8.0.16-2.el7.x86_64.rpm-bundle.tar
#安装
[root@bogon mysql]# rpm -ivh mysql-community-common-8.0.16-2.el7.x86_64.rpm 
[root@bogon mysql]# rpm -ivh mysql-community-libs-8.0.16-2.el7.x86_64.rpm 
[root@bogon mysql]# rpm -ivh mysql-community-libs-compat-8.0.16-2.el7.x86_64.rpm 
[root@bogon mysql]# rpm -ivh mysql-community-client-8.0.16-2.el7.x86_64.rpm 
 
[root@bogon mysql]# rpm -ivh mysql-community-server-8.0.16-2.el7.x86_64.rpm 
 安装完成之后 如上2.4以后操作