mysql version like this

mysql -V
mysql Ver 15.1 Distrib 10.1.44-MariaDB, for debian-linux-gnu (x86_64) using readline 5.2

I want to start mysql.service

systemctl start mysql.service
Failed to start mysql.service: Unit mysql.service not found.

service mysql start
Failed to start mysql.service: Unit mysql.service not found.

apt-get install mysql-server
Reading package lists… Done
Building dependency tree
Reading state information… Done
You might want to run ‘apt –fix-broken install’ to correct these.
The following packages have unmet dependencies:
mariadb-server : Depends: mariadb-server-10.1 (>= 1:10.1.44-0ubuntu0.18.04.1) but it is not going to be installed
mysql-server-5.7 : Depends: mysql-client-5.7 (>= 5.7.31-0ubuntu0.18.04.1) but it is not going to be installed
Depends: mysql-server-core-5.7 (= 5.7.31-0ubuntu0.18.04.1) but it is not going to be installed
Depends: libevent-core-2.1-6 (>= 2.1.8-stable) but it is not going to be installed
E: Unmet dependencies. Try 'apt –fix-broken install’ with no packages (or specify a solution).