Can't grant privileges to “root” when it has no password in MariaDB

Question

I am setting up a small development local server (is a VM running CentOS 7) and because of that I didn't add any password to MySQL after run the command: mysql_secure_installation. Now I need to connect from the host through MySQL Administrator but I can't because the user root isn't allowed to connect from the host IP address so I am gonna to change that by giving root all privileges and the host.

This is what I have done so far:

$ mysql -uroot -p
Enter password:  [here is just ENTER because root hasn't a password]
Server version: 10.1.18-MariaDB MariaDB Server

MariaDB [(none)]> GRANT ALL PRIVILEGES ON *.* TO 'root'@'192.168.3.%' WITH GRANT OPTION;
ERROR 1133 (28000): Can't find any matching row in the user table

I have found that error so I do some research on Google and found a bunch of links so I pick some of them like this one and tried:

MariaDB [(none)]> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.01 sec)

MariaDB [(none)]> GRANT ALL PRIVILEGES ON *.* TO 'root'@'192.168.3.%' WITH GRANT OPTION;
ERROR 1133 (28000): Can't find any matching row in the user table

But still not working, is a restriction and I am not aware? is a configuration on the my.cnf file? is a problem in the SQL query? Any help?

Answer 1

"If the NO_AUTO_CREATE_USER SQL_MODE is set, users can only be created with a CREATE USER statement. In this case GRANT will produce an error when the specified user does not exist." -- https://mariadb.com/kb/en/mariadb/grant/

If that is the case, then the solution is probably:

CREATE USER 'root'@'192.168.3.%';
GRANT ... (as you tried)

"Can't find any matching row..." means that there was no row with both user='root' and host='192.168.3.%'. You were coming in with user='root' and host='localhost' (or something like that).