Re: NULLs in columns referencing foreign keys

Posted in 1997

Dave Thomas — 28 Apr 1997 03:36:29 GMT — source: Informix-list mailing list archive (1991-1998)

On Sat, 26 Apr 1997 11:06:39 +0100, David Williams wrote: > In article <slrn5m2cae.ec0.dave@fast.thomases.com>, Dave Thomas > <dave@fast.thomases.com> writes > > > >Someone in the office has got me thinking about the use of NULLs in columns > >that reference other tables. > > ANY CONDITION IR EXPRESSION THAT INVOLVES NULL ALWAYS EVALUATES TO > NULL WHICH IS FALSE. Except I thought that technically NULL is unknown, not FALSE. Hence my question. Dave -- _________________________________________________________________________ | Dave Thomas - Dave@Thomases.com - Unix and systems consultancy - Dallas | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~