Hi,

I have a custom object (inspection) which has a lookup to the account object. The account object also has a formula field called SPAN. In an Apex class I'd like to create an inspection with a lookup to an account. It's a little weird how the data comes to the class but here it is:

@RestResource(urlMapping='/inspection/*')
global with sharing class InspectionRestController{
   global class RequestBody {
       global Inspection__c inspection;
   }

    @HttpPost
    global static Inspection__c create(InspectionRestController.RequestBody req) {
        Inspection__c newInspection = req.inspection;
        
        if (req.inspection.Account__r != null) {
            String span = req.inspection.Account__r.SPAN__c;
            
            Account account = [select Id from Account where SPAN__c = :span];
            
            newInspection.Account__c.Id = account.Id;
        }
    
        insert newInspection;
        return newInspection;
    }
}

I've tried to attach the account to the inspection in every way possible (new Account(Id = account.Id), etc...). I know I'm getting the correct account by the query because I've logged it out during debugging. 

Any idea what I'm doing wrong?

Thanks