To use relational or not to use relational?

#1 (**permalink**) 28-Jul-2006, 08:39 AM

I have already received some excellent advice from this group regarding my
attempts to understand relational database design so I hope you don't mind
if I seek your help once more.

Briefly, I am trying to build a database in MS Access to track my online
auction activities. Data entry for each item sold takes place over a period
of time: a) the initial placement, b) details of the winning bid, c)
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/information-technology/13766-to-use-relational-not-use-relational.html
despatch data, and so on. Therefore, I need to create forms to handle each
of these procedures with, of course, everything tied into an auction number
and an item name.

I have tried creating several tables with fields pertaining to each section
and using related links back to the auction number/item fields in the first
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=13766
table - but with little success.

It came to me, however, that I am doing too much work. Surely creating one
table with all the fields required for all sections and then creating forms
from that would work. Do I really need to bother with related fields and
multiple tables? Surely having one table will enable me to pull the auction
number/iten name fields into each form I create without the hassle of using
related links.

My question - finally - is does this sound reasonable or am I missing
something blindingly obvious?

I can see the use of relational databases when dealing with otherwise
'standalone' items like stock lists, customer contacts, etc., but where
tracking something as integral as an auction item is concerened do I need a
relational database?

You advice, as always, would be very welcome.

#2 (**permalink**) 28-Jul-2006, 08:39 AM

What you are describing is called a 1-1 relation: one record on one table
correspond to exactly one record in the other table(s). (1 or zero to be
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=13766
more precise but that's not important here). Excerpt for some exceptions,
like a great number of columns or a security problem, 1-1 relations are not
very useful; hence your question.

You will see the real advantage of relations when you will begin to use 1-N
and N-N relations. For example if you when to store *all* the bids for an
item.

--
Sylvain Lafontaine, ing.
MVP - Technologies Virtual-PC
E-mail: http://cerbermail.com/?QugbLEWINF

"Rick B" wrote in message
news:wdydnfVxIfUdf1_ZRVnyqQ@bt.com...
>I have already received some excellent advice from this group regarding my
>attempts to understand relational database design so I hope you don't mind
>if I seek your help once more.
>
> Briefly, I am trying to build a database in MS Access to track my online
> auction activities. Data entry for each item sold takes place over a
> period of time: a) the initial placement, b) details of the winning bid,
> c) despatch data, and so on. Therefore, I need to create forms to handle
> each of these procedures with, of course, everything tied into an auction
> number and an item name.
>
> I have tried creating several tables with fields pertaining to each
> section and using related links back to the auction number/item fields in
> the first table - but with little success.
>
> It came to me, however, that I am doing too much work. Surely creating one
> table with all the fields required for all sections and then creating
> forms from that would work. Do I really need to bother with related fields
> and multiple tables? Surely having one table will enable me to pull the
> auction number/iten name fields into each form I create without the hassle
> of using related links.
>
> My question - finally - is does this sound reasonable or am I missing
> something blindingly obvious?
>
> I can see the use of relational databases when dealing with otherwise
> 'standalone' items like stock lists, customer contacts, etc., but where
> tracking something as integral as an auction item is concerened do I need
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=13766
> a relational database?
>
> You advice, as always, would be very welcome.
>

#3 (**permalink**) 28-Jul-2006, 08:40 AM

Relational databases are particularly useful when you create a one to many
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=13766
connection. ie similar to - user has a car model 'A' and year 'B' and you
have a second table with lots of information already populated about all the
different types of car that exist. hence ist is easy to dertermine (say) the
horespower of the car and whether it is a station wagon or RV.

If all of your related records in one table are related to only one record
(each) in the secoind table. you simply dont need two tables.
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=13766

"Rick B" wrote:

> I have already received some excellent advice from this group regarding my
> attempts to understand relational database design so I hope you don't mind
> if I seek your help once more.
>
> Briefly, I am trying to build a database in MS Access to track my online
> auction activities. Data entry for each item sold takes place over a period
> of time: a) the initial placement, b) details of the winning bid, c)
> despatch data, and so on. Therefore, I need to create forms to handle each
> of these procedures with, of course, everything tied into an auction number
> and an item name.
>
> I have tried creating several tables with fields pertaining to each section
> and using related links back to the auction number/item fields in the first
> table - but with little success.
>
> It came to me, however, that I am doing too much work. Surely creating one
> table with all the fields required for all sections and then creating forms
> from that would work. Do I really need to bother with related fields and
> multiple tables? Surely having one table will enable me to pull the auction
> number/iten name fields into each form I create without the hassle of using
> related links.
>
> My question - finally - is does this sound reasonable or am I missing
> something blindingly obvious?
>
> I can see the use of relational databases when dealing with otherwise
> 'standalone' items like stock lists, customer contacts, etc., but where
> tracking something as integral as an auction item is concerened do I need a
> relational database?
>
> You advice, as always, would be very welcome.
>
>
>

#4 (**permalink**) 28-Jul-2006, 08:40 AM

Consider this:

You have a bid list of names, addresses, etc. Do you really want to re-enter
all of that information every time John Smith bids? OK, now the items you
are auctioning, are they unique? Do you ever sell the same thing a second
time, or have multiples to sell? How about places you auction? Do you sell
at the same place every time? Do you want to re-enter that information every
time?

Can you see the reason for relational tables now?
--
Arvin Meyer, MCP, MVP
Microsoft Access
Free Access downloads
http://www.datastrat.com
http://www.mvps.org/access

"Rick B" wrote in message
news:wdydnfVxIfUdf1_ZRVnyqQ@bt.com...
>I have already received some excellent advice from this group regarding my
>attempts to understand relational database design so I hope you don't mind
>if I seek your help once more.
>
> Briefly, I am trying to build a database in MS Access to track my online
> auction activities. Data entry for each item sold takes place over a
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=13766
> period of time: a) the initial placement, b) details of the winning bid,
> c) despatch data, and so on. Therefore, I need to create forms to handle
> each of these procedures with, of course, everything tied into an auction
> number and an item name.
>
> I have tried creating several tables with fields pertaining to each
> section and using related links back to the auction number/item fields in
> the first table - but with little success.
>
> It came to me, however, that I am doing too much work. Surely creating one
> table with all the fields required for all sections and then creating
> forms from that would work. Do I really need to bother with related fields
> and multiple tables? Surely having one table will enable me to pull the
> auction number/iten name fields into each form I create without the hassle
> of using related links.
>
> My question - finally - is does this sound reasonable or am I missing
> something blindingly obvious?
>
> I can see the use of relational databases when dealing with otherwise
> 'standalone' items like stock lists, customer contacts, etc., but where
> tracking something as integral as an auction item is concerened do I need
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=13766
> a relational database?
>
> You advice, as always, would be very welcome.
>

#5 (**permalink**) 28-Jul-2006, 08:40 AM

Once again, thank you for your prompt and helpful advice. I am beginning to
understand things a little better now.
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=13766

Rick