How can I check a version of installed ODBC MariaDB connector?
file won't give much information:

file libmaodbc.so
libmaodbc.so: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, BuildID[sha1]=5a3305eade1036378d57e16dcb09e02d541cc6a9, with debug_info, not stripped


A run of strings and grep commands gave me the version quite easily:

jynus@sangai:~/Downloads$ strings mariadb-connector-odbc-3.0.9-ga-debian-x86_64/lib/libmaodbc.so | grep -A10 ^_client_version
_client_version
_server_host
_pid
_platform
libmariadb
3.0.9
Linux
x86_64
MYSQL_PWD
5.5.5-
compiled_in


However, that doesn't seem to match the release version well:

jynus@sangai:~/Downloads$ strings mariadb-connector-odbc-2.0.18-ga-debian-x86_64/lib/libmaodbc.so | grep -A10 ^_client_version
_client_version
_pid
_platform
_server_host
libmariadb
2.3.6
Linux
x86_64
client
MYSQL_PWD
5.5.5-


I found another string like this, which seems to match the released version:

jynus@sangai:~/Downloads$ strings mariadb-connector-odbc-2.0.18-ga-debian-x86_64/lib/libmaodbc.so | grep ma-
[ma-2.0.18]
jynus@sangai:~/Downloads$ strings mariadb-connector-odbc-3.0.9-ga-debian-x86_64/lib/libmaodbc.so | grep ma-
[ma-3.0.9]
jynus@sangai:~/Downloads$ strings mariadb-connector-odbc-3.1.1-ga-rhel7-x86_64/lib/libmaodbc.so | grep ma-
[ma-3.1.1]


Use that command to find the version. Your mileage may vary, there may be a simpler way (e.g. using it), but this is a quick and dirty option.