How to ensure all Postgres queries have WHERE clause?

Question

I am building a multi tenant system in which many clients data will be in the same database.

I am paranoid about some developer forgetting to put the appropriate "WHERE clientid = " onto every query.

Is there a way to, at the database level, ensure that every query has the correct WHERE = clause, thereby ensuring that no query will ever be executed without also specifying which client the query is for?

I was wondering if maybe the query rewrite rules could do this but it's not clear to me if they can do so.

thanks

Answer 1

Deny permissions on the table t for all users. Then give them permission on a function f that returns the table and accepts the parameter client_id:

create or replace function f(_client_id integer)
returns setof t as
$$
    select *
    from t
    where client_id = _client_id
$$ language sql
;

select * from f(1);
 client_id | v 
-----------+---
         1 | 2