Login in psql

psql -U postgres -h localhost

See list of database

\l 

See list of users with list of roles

\du

Create new user

CREATE USER <username> WITH ENCRYPTED PASSWORD '<password>';

Create new database

CREATE DATABASE <databasename> WITH OWNER <username>;

DELETE database

DROP DATABASE IF EXISTS <databasename>;

GRANT Privilages

GRANT ALL PRIVILAGES ON DATABASE <databasename> TO <username>;

Import a dump file

psql -U username -d database_name -f dump.sql