I am in the midst of designing a personal database for keeping track of wines. After perusing through several beginner books on MySQL and PHP, I have decided that my next step would be to embark upon database design.
My design is almost complete and normalized, although I do expect to be making many tweakings as my knowledge progresses. I have come to a brick wall on one facet of my design, however. I've come to understand that having a lot of NULLs in your database may be a sign of a poor design. And yet I'm having a problem reconciling this with the wildly un-uniform world of wines from around the world. For instance, I would like to have a table called "GrapeVariety," and have the variety_id be a primary key. Another table would be "Wine." And yet, one wine could have one type of grape or more. For instance, let's say that wine XYZ has 80% GrapeA, and 20% GrapeB. Since my grape variety would presumably be a foreign key in the Wine table, how could I specify a certain *percentage* of a foreign key? I've tried hashing this out in numerous ways, including the addition of a "Blend" table with multiple primary keys, but anyway I slice it, there will still be an abundance of NULLs. For while the majority of wines may only contain one grape, there could be wines that have up to 5 or 6 in varying percentages. My apologies if this is inappropriately posted to this list (i.e. sorry for all the "wine"-ing). Any links or suggestions as to where I may find answers to database design issues would be greatly appreciated. bjc- :::::====== Brian J. Colaluca - Software Engineer :::::====== DRS Technologies - ESG =========== [EMAIL PROTECTED] =========== phone: (301) 921-8107 --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
