On Aug 11, 2006, at 4:08 PM, Chuck, Charlie and Charles wrote:
Jason Dixon wrote:
No offense, but given the design criteria Thomas mentioned earlier
(iCal-like), doesn't it make more sense to use a "free field" method?
That is, to create a single table of "contact" key/value pairs
associated with the user id? Then you can easily pull all pairs
associated with the user and arrange them according to a known set of
keys (first_name, last_name, email, phone, im_contact, etc).
This approach has worked well in the past for systems like OTRS.
Just
my $0.02.
I don't like it because it makes things like sorting multiple
contacts,
sorting by numeric/non-numeric fields, and having fields like check
boxes, drop-down lists, etc. needlessly complicated. In essence I
don't
like it because the more features you want to implement, the more
you've
moved towards creating a database engine on top of a database engine.
In other words there's already a system for creating paired fields and
values, and it's called a table.
With the system you propose you gain:
1) some flexibility in creating and removing fields
2) some storage space
but you lose all of the built in functions of a database engine,
such as
default data, data types (including date manipulation), etc. What
about grouping bits of that data together? Let's say you want a
list of
all phone numbers for a contact. In a normal contact table you just
hang a table off of it called phone_numbers {phone_id; contact_id;
description; phone_number} and voila, you have lists of phone numbers.
Now imagine trying to do that in the systems being proposed. Sure you
can create a single phone number label, but what if you want to allow
them to label the phone numbers with "home" "work" "cell" etc. You
either have to put that data in the "data" portion, mixing it with the
phone numbers (forget about ever sorting by area code), or you have to
create unique labels for each type, but then they can't be grouped
without having another table grouping all of them by their label.
You're absolutely right. Allow me to share with you a puff of
whatever I must have been smoking. ;-)
--
Jason Dixon
DixonGroup Consulting
http://www.dixongroup.net
