Downgrade Mysql to 5.6 from 5.7 on Ubuntu 16.04(xenial)
Ubuntu 16.04 only provides packages for MySql 5.7(by default) which has a range of backwards compatibility issues with code written against older MySql versions. for Rails specific see this
Oracle maintains a list of official APT repositories for MySql 5.6, but those repository do not yet support Ubuntu 16.04, However the 15.10 repos will work for 16.04.
Uninstall MySql 5.7 in any exists:
sudo apt remove mysql-client mysql-server mysql-comman libmysqlclient-dev
Check you removed everything
sudo dpkg -l | grep mysql
Purge reminders (e.g. merged with rc) with
sudo dkpg P <package> [<package>]
Download the apt_config-debain package from Oracle and install it
sudo dpkg -i mysql-apt-config_0.8.0-1_all.deb
Choose “MySQL 5.6” and RUN
sudo apt-cache policy mysql-server
If this shows a 5.6 version, continue.
If not, check your
/etc/apt/sources.list.d/mysql.list. It should look roughly like this:
### THIS FILE IS AUTOMATICALLY CONFIGURED ### # You may Ubuntu 16.04 only provides packages for MySQL 5.7 which has a range of backwards # compatibility issues with code written against older MySQL versions.comment out entries # below, but any other modifications may be lost. # Use command 'dpkg-reconfigure mysql-apt-config' as root for modifications. deb http://repo.mysql.com/apt/ubuntu/ wily mysql-apt-config deb http://repo.mysql.com/apt/ubuntu/ wily mysql-5.6 deb http://repo.mysql.com/apt//ubuntu/ wily mysql-tools deb-src http://repo.mysql.com/apt/ubuntu/ wily mysql-5.6 ### You might have to replace "xenial" with "wily". Although you are using 16.04 (codename Xenial), ### Oracle currently seems to only provide 5.6 in the repos for 14.04 (codename Wiley). But ### those sources work for 16.04, too.
Create a file
/etc/apt/preferences.d/mysql with this content
Package: * Pin: origin "repo.mysql.com" Pin-Priority: 999
sudo apt-get update
Now recipe’s run should provide
sudo apt install mysql-client mysql-server libmysqlclient-dev
You should get 5.6 versions. Extra Things I learned : Use P(purge), dpkg -l. Cheers :)