Re: Does Codd's view of a relational database differ from that ofDate& Darwin? [M.Gittens]

paul c wrote:
> Paul wrote:
> > paul c wrote:
> >
> >>i'd like to know what problem the never-ending arguments about nulls are
> >>aimed at. in mundane applications at least (which i think is where most
> >>people spend their time), what is the problem with using empty strings
> >>for unknown names or zeroes for unknown number values?
> >
> >
> > Because the empty string or zeros might also be valid values.
> > ...
>
> perhaps i confused things a little by mentioning empty strings instead
> of blanks. personally, i find it hard to care whether i know that i
> don't know a person's name or whether i simply call him him Mr. 'blank'.
> maybe i know the wrong people but most people i know are content
> with items on an invoice having a price of zero dollars (maybe i shipped
> an item an item before i knew its price) assuming this is anticipated by
> the application or preferably the db with partial invoices or somesuch
> notion. i think this is easier to explain to people than 3-valued logic.

Hear, hear! It totally escapes me how could somebody invent putting nonumeric value ("not salaried") into numeric column. For all reporting purposes unknown salary is salary equal to 0. If you want to run a report of all salaries that are wrong (and, therefore, are subject to adjustment) then, having a flag "salary entry is incorrect" is not going to help. An entry clerk that misses a digit in the salary is not going to mark it with such a flag anyway:-) Received on Mon Jun 06 2005 - 20:32:00 CEST