Job for mysqld.service failed because the control process exited with error code. see "systemctl status mysqld.service" and "journalctl -xe" for details
给/var/lib/mysql试试
chown -R mysql:mysql /var/lib/mysql
https://www.cnblogs.com/ivictor/p/5146247.html
不知道你是在什么环境下安装的MYSQL