I have just enabled the MariaDB 10.x package and installed the famous Heidi SQL from the Microsoft Store (because of the auto update and roaming settings etc.)
So I tried to connect to it. The MariaDB 5.x uses port 3306, but the 10.x uses 3307 (minor detail) However, I could not connect, because by default only localhost connections are enabled.
So I had to SSH into the nas and fix it. But using SSH did not work how it used to. I used Ubuntu (also from the Microsoft store) to `ssh myadminname@localipofnas` but got a cypher not accepted/available message. It turns out that the Synology has disabled several old insecure ciphers. So I had to provide a –c and an algorithm to use in order to get it to work.
“no matching cipher found. Their offer: aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc”
I used `-c aes128-cbc` because it was the first option in the list
Once logged in, I had to launch MariaDB mysql and give the user access within the lan and create a database:
- Search mysql (/usr/local/mariadb10/bin/mysql)
- Enter to mariadb with command line: ./mysql -u root –p
- Use the password
- Check user's:
- SELECT User, Host FROM mysql.user WHERE Host <> 'localhost';
- Granting User Connections From Remote Hosts:
- GRANT ALL PRIVILEGES ON . TO 'root'@'192.168.1.%' IDENTIFIED BY 'my-new-password' WITH GRANT OPTION;
Found it on: https://stackoverflow.com/a/51277323/169714
You can also use localhost or % instead of the ip. It depends on what you are trying to do 
MariaDB is now ready for some .Net Core
(Only my Synology NAS does not support Docker to run .Net Core…)
I am having doubts if I should try to work around it or just use a Raspberry Pi for my .Net core code.
Good luck, hope it saved someone some time!