On Tue, Feb 4, 2025 at 11:31 AM Michał Kłeczek <michal@kleczek.org> wrote:
[snip]
The query to register a visit is: insert into restaurant_visit select $user, current_date, restaurant_id, $rating from restaurant where name = $restaurant_name
It is now completely unclear what it means to change the name of the restaurant for already registered visits. Is it still the same restaurant with a different name or a different restaurant?
Or let say someone swaps names of two restaurants. That means a user that goes to the same restaurant every day would register visits to two different restaurants!
Valid concerns, which means that you add a new restaurant record when the name changes.
And there goes your unique index on phone number :)
I don't think I'd ever do that, since phone numbers can get reassigned.
Capital-L Large and old businesses probably don't even have unique indices on SSN.
