SQL

Here I gather some of the common commands for SQL databases

MySQL

Create and use new database:

CREATE DATABASE new_db;
USE DATABASE new_db;

Create a new user:

CREATE USER 'new_user'@'localhost' IDENTIFIED BY 'new_password';

Set privileges of the created user

GRANT ALL PRIVILEGES ON new_db.* TO 'new_user'@'localhost';
FLUSH PRIVILEGES;

PostgreSQL

Create a new user:

CREATE USER new_user WITH PASSWORD 'new_password';

Set privileges of the created user

GRANT ALL PRIVILEGES ON DATABASE new_db TO new_user;