Because I like to have my own DB, I tried to install MariaDB.
Here are the steps I used:
apt-get remove mysql-server mysql-client # Just to be safe that mysql isn't there apt-get autoremove apt-get install mariadb-server sudo apt-get install python-software-properties sudo apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 0xcbcb082a1bb943db sudo add-apt-repository 'deb http://mirror.netcologne.de/mariadb/repo/10.1/debian jessie main' sudo apt-get update apt-get install mariadb-server
But finally it throws this error: Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:
The following packages have unmet dependencies: mariadb-server : Depends: mariadb-server-10.3 (>= 10.3.5+maria~stretch) but it is not going to be installed E: Unable to correct problems, you have held broken packages.