Re: Can someone check this ER design please

Thinking some more about your example, What you did looks fine since you grouped together all the transfer information under an EventID and then associated to it all the getters.

Ok. So you may forget my previous answer. Your original description of the solution looks good.

What are the issues about associative and qualitative attributes (what are these attributes?).

Vicente.

Vicente Barreiro <vbarreiro_at_mediaone.net> wrote in message news:HfXp6.295$nr.19620_at_typhoon.mn.mediaone.net...
> I think that you could model this with only two tables:
>
> Owner | -0---------------*-< | Transfer
> OwnerID(PK) | |
 OwnerID
> asGiver(FK) (Part of the PK)
> | -0--------------*--< |
> OwnerID as Getter(FK) (Part of the PK)
>
> In words:
> * For each Owner we can remember its Id
> * For each Transfer we can remember who is the giver (an Owner), and who
 is
> a getter (an Owner)
> * A transfer is a group of records in the Transfer table and the primary
> key is the combination of Giver/Getter
> * For each Owner there can be none or many owners to wich he transfer
> * For each Owner there can be none or many owners from which he received a
> transfer.
> * For each Transfer we could add more info like pctg of share or credit or
> date, etc.
>
> Let's see some instances:
>
> Owner
> --------
> Uncle Rich
> AuntMoney
> BrotherPoor
>
> Transfer
> ---------
> Giver Getter
> --------- ----------
> UncleRich BrotherPoor
> UncleRich AuntMoney
> BrotherPoor AuntMoney
>
>
> Hope this helps.
>
> Vicho.
>
>
>
> Simon Kearns <skearns_at_iconz.co.nz> wrote in message
> news:3aa81fd7_at_news.nz.asiaonline.net...
> > I am building a DB for recording Land Shareholding Transfers.
> > Shares are transferred when someone dies to their relatives. i.e. split
> > amongst one or more beneficiaries
> > My design works but I'm not confident that it is completely correct.
> > 1. The big issue that concerns/confuses me is that:
> > "Owners transfer shares to other Owners"
> > i.e. therefore, an Owner is at different times both a Sharegiver and a
> > Sharegetter.
> > I solve this problem by a JOIN on tblOwner as tblSharegetter
> > 2. The other issue is questions of whether the DB tables have
 associative
 or
> > attributive qualities ( and whether it matters all that much!)
> >
> > Here's the cutdown ERD
> >
> > tblOwner
> > |OwnerID(pk)|
> >
> > has one to many relationship with
> > (one owner may be a sharegiver in zero or more TransferEvents)
> >
> > tblTransferEvent
> > |EventID(pk)|OwnerID(fk)|
> >
> > has one to many relationship with
> > (one TransferEvent may include zero or more TransferCredits)
> >
> > tblTransferCredit
> > |CreditId(pk)|EventID(fk)|OwnerID as SharegetterID(fk)| --it's this part
> > which i'm unsure about!!
> >
> > Thanks
> > Simon
> >
> >
> >
>
>
Received on Fri Mar 09 2001 - 17:36:30 CET