Column privileges choose columns. To choose rows too, give access through a view (Chapter 12).

CREATE VIEW public_products AS
SELECT name, price FROM products WHERE stock > 0;

GRANT SELECT ON public_products TO partner;

• A view reads its tables with the privileges of the view's owner, the role that created it. partner needs no privilege on products.
• The view's SELECT list chooses the columns. Its WHERE chooses the rows.
• partner cannot read products directly. Every query goes through the view.