Re: Design dilemma I can't get past
Date: Sun, 29 Dec 2002 15:10:00 GMT
Message-ID: <3e0f0d2c.705023_at_news.webshuttle.ch>
On 28 Dec 2002 20:37:21 -0800, bill_at_bhmediagroup.com (WebGuyBill)
wrote:
>Hello -- I'm a self-taught newbie. I appreciate any help you can
>offer.
>
>Using MySQL and PHP I'm designing a database for my website, which is
>all about books. My database structure is going to wind up being very
>similar to Amazon (tables for Authors, Titles, graphics, etc).
>
>Where I'm having trouble is with Categories (or Genres). Any one book
>can typically fall into as many as 8-to-10 categories. How best can I
>relate a specific title (e.g. "Moby Dick") to more than one category
>(e.g. "Literature > Thrillers > Seafaring" as well as "Animals >
>Mammals > Whales")?
>
>Do I need separate tables for each primary category (Biography,
>History, et al) and then more separate tables for each sub-category
>and sub-sub-category?
>
>Thanks so very much for any help!
As to referential integrity, you have to watch out that you include only categories in the linking table which are in distinct branches of the tree for any one book ... but I'm not sure that MySQL supports R.I. anyway, so it's probably a mute point.
Good luck!
Bob Hairgrove
rhairgroveNoSpam_at_Pleasebigfoot.com
Received on Sun Dec 29 2002 - 16:10:00 CET