Start MySQL database prompt in centOS7: Failed to start mysqld.service: Unit not found

phenomenon:

Start the MySQL database prompt in centOS7:

Failed to start mysqld.service: Unit not found

It's already installed, why doesn't the prompt exist?

the reason:

In CentOS7, mysql is no longer supported, even if you have already installed it, CentOS7 still expresses dislike.

solution:

Install MySQL's new open source version: MariaDB
MariaDB is like a shadow version of MySQL. MariaDB database is a branch version of MySQL, not a derivative version (folk), and it provides functions that are fully compatible with MySQL.

1. First, you need to install mariadb-server

yum install -y mariadb-server

2. Start the service

systemctl start mariadb.service

3. Add to boot

systemctl enable mariadb.service

4. Make some security settings and modify the database administrator password

mysql_secure_installation

5. MySQL opens remote access permissions for root

use mysql；
select User,authentication_string,Host from user；

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY '123456';
flush privileges;

exit;

possible problems:

MariadDB reports an error when starting

Job for mariadb.service failed because the control process exited with error code. See "systemctl status mariadb.service" and "journalctl -xe" for details.

Solution:

[root@cdh01 mysql]# cp /usr/share/mysql/my-huge.cnf /etc/my.cnf
cp: overwrite ‘/etc/my.cnf’? y
[root@cdh01 mysql]# systemctl start mariadb.service