Re: So what's null then if it's not nothing?

I think nulls may have been done to death in the literature. Date, Darwen and Pascal have written reams on the matter (and convincingly so - I don't think anyone would argue they are theoretically correct, just whether practically it matters). The problems all arise from english, and how we formulate sentences. Consider:

1. The dog's colour is black
2. The dog's colour is unknown

These look simliar in structure, but that's purely because of how we verbalise them. In terms of logic they are completely disparate statements and translate to:

1. DOG has_colour BLACK
2. DOG has_unknown_property COLOUR

Clearly there is no room for a null, or unknown element here, and stated formally the two sentences look very different. Nonetheless these are two very differently structured _facts_ about the world, that just should be encoded in the db correctly. Received on Thu Nov 17 2005 - 12:39:01 CET