Msg: 3516 *Conference*

12-06-92 15:18:28

From: RICHARD HANSON

To : HOWARD WAGGNER

Subj: REPLY TO MSG #3509 (INTER ACT)

Howard: The term "database" is a general term.  It means different things to
different folks.  There are simple databases and complex ones.  Your
application, requiring the tracking and reporting of an unknown number of
prople per photograph is not simple.  It's not highly complex, either, but not
just a flat file.  I would look at your application from a relational point of
view.  But first, some explanations...
 
FLAT FILE: This is a base of data wherein all the information tracked and
reported from is stored in one record per entity.  Each record is made from a
fixed, and equal number of fields, which are defined at the time the base
design is determined--this is done by the person setting up the base.  Each
recored recorded into the base design need not have data available for each
field but will have each field presented for the record.  No record in the base
may have a field not set-up in the overall base design.  Thus, each record in
the base is equal in number of fields, length, or as delimited.
 
Using the flat file as an example, if you need to record the same information
for several records, then you must reenter that information in each and every
record that you want it presented.  For simple data tracking applications, the
flat file works well.  It's simple to set up, use and maintain.  But, the flat
file is not a good choice in applications wherein significant amounts of data
is duplicated, or were data elements are constantly changing.
 
RELATED FILE: This is a base of data wherein all the information tracked is
stored in separate flat files, based on the needs of the data.  Reporting, on
the other hand, is accomplished by means of relating data from two or more flat
files, based on a common element.  The actual data reported on comes from
physical files.  The report, on the other hand, is known as a logical file;
existing at report time, only.
 
Using the related file (relational database) as an example, you may collect
information about some entity (i.e., customer information) in one file, then
track each customer purchase in another file (i.e., transaction information).
Responding to a quary like, "Who purchased what, and when?" you would draw
together the data from both the customer file and the transaction file to
present a logical file containing a listing of by customer of what they
purchased, perhaps sorted by item, or perhaps to send a billing to that
customer for what they purchased (on time, for instance) over a spicified time
period.
 
---
 
With the above in mind, your application requires changing data per event,
i.e., different people in each photo.  You want to ask questions like, "What
photos did so-n-so appear in?", or, "List photos werein so-n-so and whathisface
appeared, together."  These are complex questions, requiring a relationships
between the data collected, not obvious within the structure of any one record.
I would say that you will need to record your data, first by photo number, and
something about the photo in one file.  You would then create a second file
with photo number, and name fields.  Reporting would then be a matter of
relating the photo number from each file, coupled with various ways to list out
the relations, i.e., sorted by person, or by someone and someone else, or
someone, but not someone else, etc.
 
Now to your question about use of a spreadsheet program for data collection and
reporting: The spreadsheet program can be used to track data but only flat file
tracking and reporting.  There are, of course, report generator program that
will relate spreadsheet files but none are available for Model T's; not to say
that one could not be programmed.
 
As to your question about subscribing to Portable 100 Magazine, Portable
Computing, or whatever they are going to call it, vs. the "stories" you've
heard.  First, their number is: 603-924-9455.  As for the "stories" about them
not shipping on time, etc., they are true but they are the only magazine
devoting "anything" to Model T computing.  Besides, should they decide to go
South for the winter, or longer, you will be out a total of $19.95.  This is
not a biggie in my book from your point of view.  However, if they go South, I
will have spent $1,500 per month for nothing. I intend to hang in there, so you
might want to hang in there with the rest of us.  You have the least to loose
and the most to gain.
 
Thanks for your questions... -Rick-