Answers for "create user with password in postgresql"

create db user postgres

sudo -u postgres psql
postgres=# create database mydb;
postgres=# create user myuser with encrypted password 'mypass';
postgres=# grant all privileges on database mydb to myuser;

Make a user in Postgresql

CREATE USER jonathan;
CREATE USER davide WITH PASSWORD 'jw8s0F4';
CREATE USER miriam WITH PASSWORD 'jw8s0F4' VALID UNTIL '2005-01-01';
CREATE USER manuel WITH PASSWORD 'jw8s0F4' CREATEDB;

postgres create admin user with password

sudo -u postgres createuser -s -i -d -r -l -w <<username>>
sudo -u postgres psql -c "ALTER ROLE <<username>> WITH PASSWORD '<<password>>';"