Re: More than 254 cols in table?

From: Steven Whatley <swhatle_at_starbase.neosoft.com>
Date: 2 Mar 1995 16:06:10 GMT
Message-ID: <3j4qdi$62u_at_uuneo.neosoft.com>

Doug Harris (ah513_at_FreeNet.Carleton.CA) wrote:
: In a previous posting, L. Scott Johnson (sjohnson_at_math.scarolina.edu) writes:
:
: > No logical reason? What if you add or change questions?
 

: As I posted previously, it doesn't happen. Survey designs are no
: less stable than database designs.
 

: > Try:
: > Survey(Survey_ID, Name, Other_Data...)
: > Questions(Survey_ID, Question_ID, Query)
: > Response(Respondant_ID, Survey_ID, Question_ID, Answer);
: >
: > Also, try querying the number of 'Yes' responses you got.
 

: To all questions? Thats a fairly useless statistic. I'm more likely
: to want to know the average number of telephones per household for
: each city.

I do understand that the above question was quite useless. Again, it comes down to design. The common attributes associated a telephone needs to be a column in the same table as the phone number like your example below.

: ID: _______ City: _______ Telephones:_________

Now for questions such as "Which word processor did you buy in the last six months?", "How many copies did you buy?", and "Do you plan to upgrade when a new version comes availible?" would work better with a scheme like the one mentioned above. At least, it would seem that way to me.

This is a very good thread. Creating a enormous database with an item whcih could have many, many attributes is a difficult problem. With the current technology, compromises have to be made. Determining where to or not to compromise is the crux of the problem (and why some people get paid the big bucks). I look forward to reading the articles to come

Later,
Steven

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Scientific Applications International Corporation (An employee-owned company) Received on Thu Mar 02 1995 - 17:06:10 CET