From: Mark Greene Newsgroups: comp.databases.theory Subject: Re: hierarchical database and normalization Date: Sat, 09 Sep 2000 13:40:52 GMT Organization: Deja.com - Before you buy. Lines: 49 Message-ID: <8pdel2$jqa$1@nnrp1.deja.com> References: <8p97hn$s02$1@nnrp1.deja.com> <8p98fd$t8k$1@nnrp1.deja.com> <8p99el$ubj$1@nnrp1.deja.com> <39ba236b.11074494@News.CIS.DFN.DE> NNTP-Posting-Host: 152.163.207.211 X-Article-Creation-Date: Sat Sep 09 13:40:52 2000 GMT X-Http-User-Agent: Mozilla/4.0 (compatible; MSIE 5.0; AOL 5.0; Windows 95; DigExt) X-Http-Proxy: 1.0 x68.deja.com:80 (Squid/1.1.22) for client 152.163.207.211 X-MyDeja-Info: XMYDJUIDgreenemj In article <39ba236b.11074494@News.CIS.DFN.DE>, spamfilter@rosinowski.de wrote: > >Hmmm... not quite equivalent. The db I'm doing is from my coin > >collection, and I'm using the defacto cataloging method for the hobby: > > > >Country > >Denomination > >Series > >Type > >Variety > >Year > >Variation > > what kind of hierarchy is there? these are all properties of a > coin-table?! As I have it now, they are all individual tables. As your read down the list, each succeeding table is a dependant table on the previous: Country is the top table, ID is an abbreviation, and the only col is the full name. Denomination is unique to each country (US and Canada both have dimes, but only the US had a half-dime), and includes cols. for denomination name, if it is the "unit of account", the decimal equivalent of the denom based on the unit of account (i.e. a dollar is the unit of account in both the USA and Canada, but not the UK; a quarter is .25 of $1), and bits for if the denom. is a coin and/or bank note. Series has to do with each denomination's designs. Canada has had Victoria, both Georges, and Elizabeth on thier coinage; USA currently has Lincoln cents, Indian head cents prior to that, and Flying Eagle cents prior to that. Each Series had it's own unique characteristics regarding diameter, weight, metallic content, specific gravity, years of production, etc. Each Series has Varieties, and each Variety was only made for a certain span of Years, and within each individual Year there are Variations to consider. HTH --- mark Sent via Deja.com http://www.deja.com/ Before you buy.