PostgreSQL is one of the popular open source relational SQL databases. If you don't have a PostgreSQL databases, you can configure one on your Windows Subsystem for Linux easily: Install PostgreSQL on WSL. The steps to install it on UNIX-alike systems are similar.
Create user
The following code snippets shows you how to create a database user.
Create user without password:
CREATE USER kontext;
Drop user:
drop user kontext;
Create user with password:
CREATE USER kontext WITH PASSWORD 'kontext';
Create user with password and also expiry date:
CREATE USER kontext WITH PASSWORD 'kontext' VALID UNTIL '2021-12-01';
Create user with password and roles:
CREATE USER kontext WITH PASSWORD 'kontext' VALID UNTIL '2021-12-01' CREATEDB CREATEROLE;
The above statement creates a user with two default roles: create database and create role.
Show or list users
\du
Example output:
postgres=# \du
List of roles
Role name | Attributes | Member of
-----------+------------------------------------------------------------+-----------
kontext | Create role, Create DB +| {}
| Password valid until 2021-12-01 00:00:00+11 |
postgres | Superuser, Create role, Create DB, Replication, Bypass RLS | {}