Read-only user in postgres

1. Connect as admin
2. create user:
   CREATE USER 'uuu' PASSWORD 'ppp'
3. switch to necessary db (if not already):
   \connect ddd
4. add rights:
GRANT CONNECT ON DATABASE ddd TO uuu;
GRANT USAGE ON SCHEMA public TO uuu;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO uuu;


This only affects tables that have already been created. More powerfully, you can automatically have default roles assigned to new objects in future:

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