How to retrieve the current version of a MySQL database management system (DBMS)?

Many answers suggest to use mysql --version. But the mysql programm is the client. The server is mysqld. So the command should be

mysqld --version

or

mysqld --help

That works for me on Debian and Windows.

When connected to a MySQL server with a client you can use

select version()

or

select @@version

Try this function -

SELECT VERSION();
-> '5.7.22-standard'

VERSION()

Or for more details use :

SHOW VARIABLES LIKE "%version%";
+-------------------------+------------------------------------------+
| Variable_name           | Value                                    |
+-------------------------+------------------------------------------+
| protocol_version        | 10                                       |
| version                 | 5.0.27-standard                          |
| version_comment         | MySQL Community Edition - Standard (GPL) |
| version_compile_machine | i686                                     |
| version_compile_os      | pc-linux-gnu                             |
+-------------------------+------------------------------------------+
5 rows in set (0.04 sec)

MySQL 5.0 Reference Manual (pdf) - Determining Your Current MySQL Version - page 42