Install drivers for MySql or MariaDb
This is not necessary with Ubuntu, up to release 14.04.
On other systems, in particular Ubuntu >= 16.04, you must install yourself a driver depending on your exact Linux distribution.
Open a terminal and execute the following command :
find /usr/lib -name libmysqlclient??
If no file is found, you should be able to install the required driver with the following command. After that, rerun the find :
sudo apt-get install libmysqlclient??
If a file is found, copy it's full pathname (e.g /usr/lib/x86_64-linux-gnu/libmysqlclient.so.20), and run :
sudo ln -s /usr/lib/x86_64-linux-gnu/libmysqlclient.so.20 /usr/lib/x86_64-linux-gnu/libmysqlclient.so