You can't patent an idea. You can patent the implementation of it if you're specific enough.

Well sort of. You don't need to have built the actual thing to get a patent.

You cannot patent the completely generic idea of "a tool to lift people in buildings", but you can patent an elevator.

Similarly, you cannot patent "the ability to scan a database", but you can patent an api for doing so, even without a complete implementation of that api.

> You cannot patent the completely generic idea of "a tool to lift people in buildings",

You should see some of the software patents that get approved nowadays to see just how often "idea on a computer" gets greenlit.

Like that Sony patent from 2005 to control the brain without conducting any experiments to confirm if that even works:

https://arstechnica.com/uncategorized/2005/04/4785-2/