If you know that changes happened outside of EF and want to refresh your ctxt for a specific entity, you can call ObjectContext.Refresh
datamodel.Refresh(RefreshMode.StoreWins, orders);
If this seems like it will be a common occurance, you should disable object caching in your queries:
SchoolBriefcaseEntities datamodel = new SchoolBriefcaseEntities();
datamodel.tblCities.MergeOption = MergeOption.NoTracking;
or for to turn off object level caching for specific Entity,
Context.Set<Compliances>().AsNoTracking();