Cannot login to MySQL database after fresh install with root ID and empty/no password like other older MySQL versions do.
After you installed MySQL-community-server 5.7 from fresh on linux, you will need to find the temporary password from /var/log/mysqld.log to login as root.
grep 'temporary password' /var/log/mysqld.log
mysql_secure_installation
to change new passwordref: http://dev.mysql.com/doc/refman/5.7/en/linux-installation-yum-repo.html