Linux-Ubuntu: Installing MySQL Server failed: - mysql

Question

I have installed apache2, installed php 7. installed phpmyadmin.
Then i tried to create a database with the user i created. Unfortunately i was not able to create a database because i did not have the right permissions. So i decided to start from scratch and deleted everything (apache2, mysql, php, phpmyadmin).
To delete the MySQL server i used the following commands±
sudo apt-get remove --purge mysql*
sudo apt-get autoremove
sudo apt-get autoclean
Now I get stuck with the installation of mysql. I think i deleted more then i should have deleted.
Reading package lists... Done
Building dependency tree
Reading state information... Done
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:
mysql-server-5.6 : PreDepends: mysql-common (>= 5.5) but it is not
installable
Depends: libdbi-perl but it is not installable
Depends: mysql-client-5.6 (>= 5.6.35-1+deb.sury.org~xenial+0
.1) but it is not going to be installed
Depends: mysql-common (>= 5.6.22-1~) but it is not installable
E: Unable to correct problems, you have held broken packages.
When i use apt-get update:
root#localhost:~# apt-get update
Hit:1 http://archive.canonical.com/ubuntu xenial InRelease
Hit:2 http://ppa.launchpad.net/ondrej/mysql-5.6/ubuntu xenial InRelease
Hit:3 http://ppa.launchpad.net/ondrej/mysql-5.7/ubuntu xenial InRelease
Hit:4 http://ppa.launchpad.net/ondrej/php/ubuntu xenial InRelease
When i use: sudo apt-get install -f
root#localhost:~# sudo apt-get install -f
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
sudo apt-get clean : returns nothing
Sudo apt-get -f install:
root#localhost:~# sudo apt-get -f install
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
sudo apt-get -o Debug::pkgProblemResolver=yes dist-upgrade
root#localhost:~# sudo apt-get -o Debug::pkgProblemResolver=yes dist-upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Starting pkgProblemResolver with broken count: 0
Starting 2 pkgProblemResolver with broken count: 0
Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Because the installation didn´t work and I get stuck with some other errors I also changed the source list file.

Answer 1

I found the solution.
In my case it has to do with my sourcelist file in etc/apt directory.
I updated the file
# deb cdrom:[Ubuntu-Studio 16.04 LTS _Xenial Xerus_ - Alpha amd64 (20151225)]/ xenial main multiverse restricted universe
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://archive.ubuntu.com/ubuntu/ xenial main restricted
deb-src http://archive.ubuntu.com/ubuntu/ xenial main restricted
bug fix updates produced after the final release of the
## distribution.
deb http://archive.ubuntu.com/ubuntu/ xenial-updates main restricted
deb-src http://archive.ubuntu.com/ubuntu/ xenial-updates main restricted
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## universe WILL NOT receive any review or updates from the Ubuntu security
## team.
deb http://archive.ubuntu.com/ubuntu/ xenial universe
deb-src http://archive.ubuntu.com/ubuntu/ xenial universe
deb http://archive.ubuntu.com/ubuntu/ xenial-updates universe
deb-src http://archive.ubuntu.com/ubuntu/ xenial-updates universe
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://archive.ubuntu.com/ubuntu/ xenial multiverse
deb-src http://archive.ubuntu.com/ubuntu/ xenial multiverse
deb http://archive.ubuntu.com/ubuntu/ xenial-updates multiverse
deb-src http://archive.ubuntu.com/ubuntu/ xenial-updates multiverse
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://archive.ubuntu.com/ubuntu/ xenial-backports main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ xenial-backports main restricted universe multiverse
## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
deb http://archive.canonical.com/ubuntu xenial partner
deb-src http://archive.canonical.com/ubuntu xenial partner
deb http://security.ubuntu.com/ubuntu xenial-security main restricted
deb-src http://security.ubuntu.com/ubuntu xenial-security main restricted
deb http://security.ubuntu.com/ubuntu xenial-security universe
deb-src http://security.ubuntu.com/ubuntu xenial-security universe
deb http://security.ubuntu.com/ubuntu xenial-security multiverse
deb-src http://security.ubuntu.com/ubuntu xenial-security multiverse
Run:
sudo apt-get update
And to apply any updates, run one of the following commands:
sudo apt-get upgrade
See the Answer