Re: NULLs ;-)

["John D. Burger" <john(at)mitre(dot)org>]

> > > where a <> b or (a is null and b is not null) or (a is not null  
> > > and b is null)
> >
> > In the absence of IS DISTINCT FROM, I think this has the same  
> > semantics:
> >
> >    where coalesce(a, b) <> coalesce(b, a)
>
> sorry, but no.

Argh, my expression is just nonsense - I was thinking of something like:

  coalesce(a, 'SOME MAGIC VALUE') <> coalesce(b, 'SOME MAGIC VALUE')

and wanted to make it work for any types.  Sigh.

- John D. Burger
  MITRE