mariadb grant use database to user code example
Example: create database and grant user rights mariadb
create database [DB name];
CREATE USER '[DB_User_Name]'@'localhost' IDENTIFIED BY '[DB_Password]';
GRANT ALL PRIVILEGES ON [DB_Name].* TO '[DB_User_Name]'@'localhost';
show grants for 'demouser'@'localhost';
FLUSH PRIVILEGES;