mysql-community-common(x86-64) >= 5.7.9 is needed by mysql-community-libs-5.7.21-1.el7.x86_64
这个时候需要解决的是将已经安装的rpm报卸载. 通过rpm -qa |grep -i mysql或者是rpm -qa |grep -i mariadb 如果找到那个执行 rpm -e 包名刚才找到的包名即可
rpm -qa |grep -i mysql
rpm -qa |grep -i mariadb
rpm -e 包名