安装前先删除残留：

[root@izwz9hy3mj62nle7573jv5z ~]# rpm -qa | grep -i mysql
[root@izwz9hy3mj62nle7573jv5z ~]# 
[root@izwz9hy3mj62nle7573jv5z ~]# find / -name mysql
/root/.jenkins/local_lib/mysql
/etc/selinux/targeted/active/modules/100/mysql
/usr/lib64/mysql
/usr/share/mysql
/usr/bin/mysql
[root@izwz9hy3mj62nle7573jv5z ~]# 

安装：

下载地址：https://downloads.mysql.com/archives/community/

# 下载
wget  https://downloads.mysql.com/archives/get/p/23/file/mysql-community-server-5.7.23-1.el7.x86_64.rpm
# 会通过rpm自动下载并且覆盖强制安装
rpm -ivh mysql-community-server-5.7.23-1.el7.x86_64.rpm --force --nodeps

卸载--rpm安装方式的卸载：

# 卸载
rpm -e xxxxxXXX.rpm

卸载--yum安装方式的卸载：

yum remove mariadb*
yum remove mysql*

访问数据库：

mysql -uroot -p

创建用户和授权：

-- 使用命令登录：mysql -u root -p
-- 创建用户 用户名：long 密码：Long@123456
create user 'long'@'%' identified by 'Long@123456';
-- 授权 *.*表示所有库
grant SELECT, REPLICATION SLAVE, REPLICATION CLIENT on *.* to 'long'@'%' identified by 'Long@123456';
GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY '123456' WITH GRANT OPTION;

忘记密码：

# 配置跳过授权
[root@izwz9hy3mj62nle7573jv5z ~]# vim /etc/my.cnf
# 如果忘记密码，配置skip-grant-tables，实现访问后跳过授权
[mysqld]
 skip-grant-tables

# 重启mysql，再次登陆无需 

重设密码：

flush privileges;
set password for root@localhost = password('123456');
flush privileges;

重设密码后注释掉skip-grant-talbes

创建用户和授权：

-- 使用命令登录：mysql -u root -p
-- 创建用户 用户名：canal 密码：Canal@123456
create user 'canal'@'%' identified by 'Canal@123456';
-- 授权 *.*表示所有库
grant SELECT, REPLICATION SLAVE, REPLICATION CLIENT on *.* to 'canal'@'%' identified by 'Canal@123456';

重启：

service mysqld restart