Re: Quote of the Week

jcelko212_at_earthlink.net (--CELKO--) writes:
> 1) Someone send Chris Date one of my very old SQL puzzles and wanted
> help with it. Chris answered it with his personal programming
> language rather than Standard SQL. The problem involved displaying
> the hire date and last promotion date for each employee in a
> personnel. The specs were to use a NULL, if the employee was a new
> hire. Since Chris Date's version of the Relational Model does not
> have NULLs, he used an arbitrary dummy date instead and thus created
> false information.

posting a year ago in this n.g.
http://www.garlic.com/~lynn/2003g.html#40 How to cope with missing values - NULLS?

mentioning a long ago and far away article by date (1992) titled "An Explanation of why three-valued logic as a mistake" ... related to the handling of NULLS in SQL.

-- 
Anne & Lynn Wheeler | http://www.garlic.com/~lynn/