Removing MySQL 5.7: A Comprehensive Guide to Purge and Uninstall

To completely remove MySQL 5.7 from an Ubuntu 12.04 system, follow these comprehensive steps:

Backup Databases

Before proceeding with the uninstallation, ensure you have backed up your essential databases using the mysqldump utility. Backup only the required databases, as a full database backup may be the root cause of the uninstalling issue.

Stop MySQL Services

• sudo service mysql stop or sudo mysqld (if installed via a package)
• sudo killall -9 mysql and sudo killall -9 mysqld (if installed from source)

Uninstall MySQL Packages

• sudo apt-get remove --purge mysql-server mysql-client mysql-common
• sudo apt-get autoremove
• sudo apt-get autoclean

Remove User and MySQL Directory

• sudo deluser -f mysql
• sudo rm -rf /var/lib/mysql

Purge MySQL Core Packages

• sudo apt-get purge mysql-server-core-5.7
• sudo apt-get purge mysql-client-core-5.7

Remove Logs and Configuration

• sudo rm -rf /var/log/mysql
• sudo rm -rf /etc/mysql

As a consolidated command, you can run the following single line to perform all the above steps:

sudo service mysql stop &&& sudo killall -9 mysql &&& sudo killall -9 mysqld &&& sudo apt-get remove --purge mysql-server mysql-client mysql-common &&& sudo apt-get autoremove &&& sudo apt-get autoclean &&& sudo deluser mysql &&& sudo rm -rf /var/lib/mysql &&& sudo apt-get purge mysql-server-core-5.7 &&& sudo apt-get purge mysql-client-core-5.7 &&& sudo rm -rf /var/log/mysql &&& sudo rm -rf /etc/mysql