Re: NULL values or Zero in numeric fields?
From: EndUser <enduser_at_enduser.com>
Date: 1995/11/30
Message-ID: <enduser-3011952126360001_at_204.247.5.10>#1/1
Date: 1995/11/30
Message-ID: <enduser-3011952126360001_at_204.247.5.10>#1/1
the correct opinion, i add.
youd be surprised how many "professionals" dont undertand this basic concept.
-- In article <49hske$osj_at_peacock.tcinc.com>, Ron Reidy <rreidy> wrote:Received on Thu Nov 30 1995 - 00:00:00 CET
> francois.lachance_at_sasknet.sk.ca (Francois Lachance) wrote:
> >We have a few tables with numeric columns. By default, if you don't
> >save a value in those columns, they are NULL values. Is there an
> >advantage to leaving these empty rows as NULL? Users that are doing
> >queries directly against the database are asking that Zero be put in
> >the rows where no value has been specified. Programmers find it
> >annoying to have to make sure that calculations are not done on NULL
> >values since it returns a NULL if you do.
> >
> >What does that do as far as data storage is concerned? Will a zero
> >take more space then a NULL?
> >
> >Thanks for any help that you can provide.
> >
> >
> >+===================================================================+
> >+ +
> >+ Francois Lachance +
> >+ Data Administrator +
> >+ Saskatchewan Highways and Transportation +
> >+ Regina, Saskatchewan +
> >+ Canada +
> >+ +
> >+===================================================================+
> >
> >
> Answers:
>
> 1. Yes there is a storage advantage to leaving columns NULL. No space is
> taken up in the table when a column is NULL.
>
> 2. Programmers are correct to not want to put 0's there. A 0 denotes
> something, NULL denotes absence of something. The difference is subtle, but
> signficant.
>
> 3. End-users need to be trained in the correct use of tools (or special tools
> bult for them). They will have to learn how the data works and what the
> significance of it is.
>
> Just my opinion, of course.
>
> rr