On Friday, June 26, 2015, Robert Nikander <rob.nikan...@gmail.com> wrote: > > So… is this bad DB design to use null to mean that an item has no color? > Should I instead put a special row in `colors`, maybe with id = 0, to > represent the “no color” value? Or is there some way to make an index work > with nulls and `is not distinct from`? >
Not sure about getting is distinct to work with indexes but in this particular case I would add a "colorless" color to the table and make the column constraint not null. I would also likely just make the text value the unique key and forget the surrogate integer key. David J.
