Check for PG::UniqueViolation exception

check_unique.rb

def create
    @provider = Provider.new(provider_params)
    begin
      if @provider.save
        redirect_to @provider
      else
        render 'new'
      end
    rescue Exception => what
      if what.message.include? "PG::UniqueViolation"
        @provider.errors.add :name, "name and url pair must be unique!"
      else
        @provider.errors.add :name, what.message
      end
      render 'new'
    end
  end