I am trying to make an office reservation calendar using a SP list. I have all the fields I want but do not want people to accidentally book the same room on the same day. However I cannot use the Require Unique Field feature because it seems like it would either allow for an office to only be chosen once, or it would only allow for one item per day.
@Micmead91 SharePoint has always been very bad a preventing clashes in this sort of scenario without resporting to custom code. My recommendation would be to look at using Power Apps as the front end and a SharePoint list as the data source. It's possible to only allow one booking a day for each room. I did this for our desk booking system during & after COVID:
There are several good videos on YouTube by April Dunnam which show you how to build a room/desk booking app, and there is a also the Book a Room app template on Power Apps though I haven't tried it.
Rob Los Gallardos Microsoft Power Automate Community Super User. Principal Consultant, SharePoint and Power Platform WSP UK (and classic 1967 Morris Traveller driver)