public void Delete(ProviderPremis entity)
        {
            var data = (from proPre in _context.ProviderPremises
                        where proPre.ProviderId == entity.ProviderId && proPre.PremisesId == entity.PremisesId
                        select proPre).FirstOrDefault();

            if (data != null)
            {
                _context.ProviderPremises.Remove(data);
            }
            else
            {
                throw new Exception("Premises does not exist.");
            }
        }
        public void AddProviderPremises(ProviderPremis entity)
        {
            var data = (from proPre in _context.ProviderPremises
                        where proPre.ProviderId == entity.ProviderId && proPre.PremisesId == entity.PremisesId
                        select proPre).FirstOrDefault();

            if (data == null)
            {
                _context.ProviderPremises.Add(entity);
            }
            else
            {
                throw new Exception("Premises already added.");
            }
        }