Re: 2 people with same address - sometimes - standard data model?y

In article <1995Jan12.085053.39116_at_bsuvc.bsu.edu>, 01tlcrabtree_at_bsuvc.bsu.edu (TIMOTHY LANE) wrote:

>In article <l.carl.pedersen-1101951942230001_at_kip-2-sn-53.dartmouth.edu>,
 l.carl.pedersen_at_dartmouth.edu (L Carl Pedersen) writes:
>> i need to track parents of students in order to send them certain mailings
>> etc. my plan is to stick them into the same table that i use for student,
>> as it already has all the columns i need etc. - so my table becomes a
>> people table.
>>
>> my issue is this: some high percentage of these parents live together at
>> the same address, but many do not (typically because they are divorced).
>>
>> for many reasons, it pains me to store *two* addresses when the addresses
>> for two people are often the same.
>>
>> i suppose i could have some sort of "household" table that is referenced
>> by the person table, but that seems sort of clumsy. one problem is that i
>> can't think of an obvious external key to let my users jump between the
>> two tables. i can't have my screens hide the fact that the addresses for
>> two people are the same, since i need some way to *change* whether they
>> are the same or not.
>>
>> oddly enough, none of our current systems seem to have any provision for
>> representating the fact that two people have the same address.
>>
>> it seems to me this must be a very common data design problem - especially
>> in the university environment.
>>
>> how do you solve this problem? is there a "standard" method?
>>
>> i should probably mention that these people are not *always* parents. in
>> reality they are people who have cosigned for the student's loans and
>> there may be zero to many of them. there is a good chance that the
>> student may be living with their "parents" for a while, thus increasing
>> the potential for duplication.
>>
>> if you send me email, i'll post a summary. thanks.
>
> Normalization of data would suggest setting up a "household"
>table. One possible unique key to this table would be the 9 digit zip
>code. It may be tedious and boring to update your current zip to 9
>digits, but it may pay-off in the future.
>
>Tim Crabtree

i don't believe 9-digit zips are unique to a household. i think, for example, that two people who live next door to each other may have the same 9-digit zip.

if you have evidence to the contrary, i'd love to see it. we are already moving toward 9-digit zips. Received on Thu Jan 12 1995 - 19:25:21 CET