On Friday, 6 March, 2020 19:25, Richard Damon <rich...@damon-family.org> wrote:
>It is sort of like NaN, where a Nan is neither less than, greater than >or equal to any value, including itself. NULL (as in SQL NULL) means "missing value" or "unknown". NULL represents any value within the domain, we simply do not know what that value is. That is, the value "NULL" for colour of a car means that we do not know the colour -- however, it still has one. NaN, on the other hand, means that the value is outside the domain and that there is no possible value of the domain which well render the proposition true. For example, the state of Schroedingers Cat is NULL. It has a state, either dead or alive. That state is merely unknown until one looks in the box. However, if when you looked in the box there was no cat, then the cat would be a NaN since its state was outside of the domain of states for a cat in a box with a time release poison after the release of the poison, that is, the non-existance of a cat in the box precludes the possibility of the state of the cat in the box being either either dead or alive. -- The fact that there's a Highway to Hell but only a Stairway to Heaven says a lot about anticipated traffic volume. _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
