mysql : downgrade from mysql community version 5.7.9 to mysql 5.1 on centos

1. service mysqld stop
2. yum remove mysql-community-server
3. yum remove mysql
4. yum repolist disable | grep "mysql.*-community.*"
5. yum install mysql
6. yum install mysql-server
7. service mysqld start

if the above script doesnt work make sure you uninstall everything that appears with then rerun this script again:

1. yum list installed | grep mysql