Granting access to all tables for a user

Question

I'm a new to Postgres and trying to migrate our MySQL databases over. In MySQL I can grant SELECT, UPDATE, INSERT, DELETE privileges on a low privileged user and enable those grants to apply to all tables in a specified database. I must be missing something in Postgres because it looks like I have to grant those privileges for each table one at a time. With many databases and hundreds of tables per database that seems like a daunting task just to get off the ground. In addition, once a database is in operation, adding tables happens frequently enough that I wouldn't want to have to grant permissions each time unless absolutely necessary.

How is this best accomplished?

Answer 1

First, you have to be able to connect to the database in order to run queries. This can be achieved by

REVOKE CONNECT ON DATABASE your_database FROM PUBLIC;

GRANT CONNECT
ON DATABASE database_name 
TO user_name;

The REVOKE is necessary because

The key word PUBLIC indicates that the privileges are to be granted to all roles, including those that might be created later. PUBLIC can be thought of as an implicitly defined group that always includes all roles. Any particular role will have the sum of privileges granted directly to it, privileges granted to any role it is presently a member of, and privileges granted to PUBLIC.

If you really want to restrict your user to DML statements, then you have a little more to do:

REVOKE ALL
ON ALL TABLES IN SCHEMA public 
FROM PUBLIC;

GRANT SELECT, INSERT, UPDATE, DELETE
ON ALL TABLES IN SCHEMA public 
TO user_name;

These assume that you will have only one schema (which is named 'public' by default).

Answer 2

assuming you want to give them all privileges - do that.

grant all privileges on database dbname on dbuser;