yum -y install mysql-community-server
Last metadata expiration check: 0:13:40 ago on Sun 26 Apr 2020 11:20:57 AM CST.
No match for argument: mysql-community-server
Error: Unable to find a match: mysql-community-server
解決：
先執行：yum module disable mysql
再執行：yum -y install mysql-community-server
配張圖有理有據：