Compare changes.

How can I compare an entry?

@edit = Data.find(4)

After this, user update some data en press submit.

How can compare, is there any changes in new @edit and what is in
database?
Have user chnged any data or pressed just submit without changes?

Try this in the #update action. It's untested:

@edited_data = Data.new(params[:data])
@original_data = Data.find(params[:id])
if @edited_data == @original_data
  # The data is NOT changed...
else
  # The data IS changed...
end

I don't know if the == operator works in this case, but try it out and
come back if you get problems. :slight_smile: