I have followed the instruction in https://registry.hub.docker.com/_/mysql/ to pull an image and running a container in which it runs a MySQL server.
The container is run
I connect to the bash into the running MySQL container:
$ docker exec -t -i container_mysql_name /bin/bash
-iis the shortcut for--interactiveoption. This options is used for keep STDIN open even if not attached
-tis the shortcut for--ttyoption, used to allocate a pseudo-TTY
I run MySQL client from bash MySQL container:
$ mysql -uroot -proot
-uis shortcut for--user=nameoption, used to define user for login if not current user.
-pis shortcut for-password[=name]option, used to define password to use when connecting to server. If password is not given it's asked from the tty.
Disco!