@Jodrell already gave you the correct answer - "setup number 2" with
compound PK is the best solution. I'll just explain it in details.
There are companies, countries and websites. For each of them we create
a separate table.
Now it's time for references:
If a company may have only one website, then it's one-to-one
relationship. If it may have many websites, then it's one-to-many
relationship. In both cases you have a foreign key CompanyId in Website
table - it'll only differ in UNIQUE constraint.
You write "Each website is targeting one or several countries."
Additionally, for every country there may be one or more websites (for
different companies). It means that it's a classical many-to-many
relationship. In such case you must add a junction table -
WebsiteCountries. Here you'll have a compound primary key that constists of
two columns: (WebsiteId, CountryId). This'll prevent from
Hope this helps.