1. Check the startup status of the mariadb service
[root@localhost ~]# systemctl status mariadb
2. If it is active (running), stop the service, if it is inactive (dead), then uninstall it directly
Out of service
[root@localhost ~]# systemctl stop mariadb
3. Uninstall service
[root@localhost ~]# yum remove mariadb -y
4. View the catalog
[root@localhost ~]# ls /etc/my.cnf
[root@localhost ~]# ll /var/lib/mysql/5. Delete files and directories
[root@localhost ~]# rm -rf /etc/my.cnf
[root@localhost~]# rm -rf /var/lib/mysql/6. Reinstall the mariadb database
https://blog.csdn.net/llwy1428/article/details/84965680
At this point, Centos7.x completely uninstalls the mariadb database operation is complete!