adding user to postgres code example
Example 1: 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;
Example 2: how to add user to role postgresql
GRANT group_role TO role1, ... ;
REVOKE group_role FROM role1, ... ;