I need it quite often during development (mainly school work) that I need to create new database together with new user that can only use this specific database. Here are three simple commands that do just that.
CREATE DATABASE robert_db; CREATE USER robert WITH ENCRYPTED PASSWORD 'x1y2z3'; GRANT ALL PRIVILEGES ON DATABASE robert_db TO robert;
In development I usually keep db name and user name the same so that I have less variables to remember.