Create an Postgres user in AWS RDS with createDB permissions

These commands are assuming you are using psql cli as such and can be executed via SQL gui also.

To create a user you will need to execute the following command

CREATE USER username with CREATEDB password 'qwerty12345';

To grant SELECT access to the database created already you will need to grant access as follows assuming the schema is public. Select the database to assign the access with with

\c databasename;

Then assign access to all future tables and views in public schema.

ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO username;

Then assign access to existing views and tables in the public schema as follows.

GRANT SELECT ON ALL TABLES IN SCHEMA public TO username;

Replace username, databasename and the random password with your own values.