I am creating a table ProjectSites that will be a child table to another table Projects and it will only have three columns, here is the current schema
ProjectSiteID identity pk
ProjectID int fk
SiteID int fk
So the idea is, there can be one or more Sites assigned to every project. There will never be a case where the same Site is assigned more than once to the same Project. My question is this, Should I make the PK of the table a combination of all three columns so that no mistakes can ever be made?