Jumat, 23 Oktober 2015

RE: [MS_AccessPros] Table Design Question

 

Jan:

I am not sure what you mean by "Crosswalk" … does that mean an OwnerID in Units and UnitID in Owners? I wouldn't recommend that.

 

If one-and-only Owner has one-or-more Units, like Invoices have InvoiceDetails, then yes, a one-to-many relationship, with the OwnerID as an FK in the Unit table makes sense.

 

However, if there is a possibility of partnerships, or multiple owners (married/separated couples?), then you should consider a junction table to facilitate a many-to-many relationship.  So you would have  a OwnerUnit table, with both an OwnerID and a UnitID (and probably start and end dates, but I am leaping ahead there.)

 

Remember in db design context "many" means the possibility of there being more than one, on that side of relationship.

 

Hth,

Steve Conklin

 

 

 

From: MS_Access_Professionals@yahoogroups.com [mailto:MS_Access_Professionals@yahoogroups.com]
Sent: Friday, October 23, 2015 10:39 PM
To: MS_Access_Professionals@yahoogroups.com
Subject: [MS_AccessPros] Table Design Question

 

 

I am setting up a database for my homeowners' association. I plan on starting with two tables.  Units and Owners. We still have a fair number of undeveloped lots so some of the owners will own multiple lots.

I can ether create an OwnerID field in the Units table or do a crosswalk. I am leaning toward putting a field in the Unit record but wondered if this is the best way. Probably no difference but I thought I would ask.

Thanks

 

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Posted by: Stephen Conklin <stephenmconklin@hotmail.com>
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