I am not sure if it will work, but try this. First you need to uninstall anything that is related to mysql:

sudo apt-get purge mysql*
sudo apt-get autoremove
sudo apt-get autoclean

Then the important bit, this error could be caused because your distribution is not upgraded recently, or at least conflicts are not resolved properly. So next thing is to upgrade it like you did before but without removing first:

sudo apt-get dist-upgrade

Now after this is done, you can try to install mysql as normal again. Hope this will work, please give a report. If it doesnt work we’ll try another fix.

IMPORTANT NOTE

AFTER PURGING AND REMOVING MYSQL. RESTART THE MACHINE.

I REPEAT “RESTART THE MACHINE”

RESTART IS THE FINAL SOLUTION. I have spent sleepless nights figuring why it’s not solving.

I was having this problem, too. I did this on Ubuntu 16.04.6

sudo apt -y purge mysql*
sudo apt -y autoremove
sudo rm -rf /etc/mysql
sudo rm -rf /var/lib/mysql*
sudo shutdown -r now

(VM reboots)

sudo apt -y install mysql-server

And it still fails:

-----

dpkg: dependency problems prevent configuration of mysql-server:
 mysql-server depends on mysql-server-5.7; however:
  Package mysql-server-5.7 is not configured yet.

dpkg: error processing package mysql-server (--configure):
 dependency problems - leaving unconfigured
Processing triggers for libc-bin (2.23-0ubuntu11) ...
No apport report written because the error message indicates its a followup error from a previous failure.
                                                                                                          Processing triggers for systemd (229-4ubuntu21.23) ...
Processing triggers for ureadahead (0.100.0-19.1) ...
Errors were encountered while processing:
 mysql-server-5.7
 mysql-server
E: Sub-process /usr/bin/dpkg returned an error code (1)

-----

So I ran this command:

mysql_secure_installation

To which I answered yes for everything, choose a MEDIUM level password validation and declined to change my root password.

Then, I ran this command:

sudo apt -y install mysql-server

And now it’s running:

service mysql status

● mysql.service - MySQL Community Server
   Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)
   Active: active (running) since Fri 2020-01-10 17:37:20 CST; 8min ago
  Process: 5527 ExecStartPost=/usr/share/mysql/mysql-systemd-start post (code=exited, status=0/SUCCESS)
  Process: 5515 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=0/SUCCESS)
 Main PID: 5526 (mysqld)
    Tasks: 28
   Memory: 117.1M
      CPU: 478ms
   CGroup: /system.slice/mysql.service
           └─5526 /usr/sbin/mysqld

Jan 10 17:37:19 do-sandbox systemd[1]: Stopped MySQL Community Server.
Jan 10 17:37:19 do-sandbox systemd[1]: Starting MySQL Community Server...
Jan 10 17:37:20 do-sandbox systemd[1]: Started MySQL Community Server.

I think I needed to configure it before it would fire up. But I still don’t know why.

try this solution using aptitude this will replace all the file corrupted

sudo aptitude install mariadb-server

instead of running this

sudo apt install mariadb-server

install aptitude in your machine using

sudo apt-get install aptitude

After purging/autoremoving/cleaning the mysql server I had to manually delete some directories since I had reconfigured some settings.

Use only if you are sure that you don’t need old configuration files and the previous database entries anymore, since /var/lib/mysql-keyring contains passwords etc. and /var/lib/mysql contains the default database location!

sudo rm -rf /etc/mysql

and

sudo rm -rf /var/lib/mysql*

Now the configuration process started normally during reinstallation of the server.

Thank you CrypticDesigns. I went through purging, removing, and cleaning multiple times before and after dist-upgrade. It didn’t work for me. Any other suggestion/ solution will be appreciated..

I get the same error. . No luck with above mentioned solutions :-(

dpkg: dependency problems prevent configuration of mysql-server:
mysql-server depends on mysql-server-5.7; however:
Package mysql-server-5.7 is not configured yet.

dpkg: error processing package mysql-server (–configure):
dependency problems - leaving unconfigured
No apport report written because the error message indicates its a followup error from a previous failure.
Processing triggers for libc-bin (2.23-0ubuntu5) …
Processing triggers for systemd (229-4ubuntu16) …
Processing triggers for ureadahead (0.100.0-19) …
Errors were encountered while processing:
mysql-server-5.7
mysql-server
E: Sub-process /usr/bin/dpkg returned an error code (1)

same problem here

I had similar problem.
Ubuntu 14.04 with preinstalled nginx + mysql 5.5. In July 2015 after one of security updates mysql doesn’t finish to install. I’ve tried shuting down mysql-server before updating without success in updating. Today I’ve tried to removing and installing again mysql-server but still the same error. Then I stopped and started mysql manually in other shell during updating in aptitude, and problem disapers (ie. on aptitude I have no error message “packages partially installed: mysql-server and mysql-server-5.5”)
I hope this will help someone.

Still having the same problem even after following @ForYourIT ’s answer. This is driving me insane.