David McAfee
DMcAfee at haascnc.com
Thu Mar 11 14:48:42 CST 2004
I our last system, we had a Zipcode table with 5 fields (and 45K+ records): ZipID (PK Autonumber) ZipCode (text,5) City (text, 30) State (text, 2) DefaultCity (yes/no) I would look up a city based on zipcode entry. One of three results could happen: 0 records returned: Prompt to check if zipcode entry (later evolved into adding new city) 1 record returned: populate city and state onto form >1 record returned: pop up a mini screen with a list box showing all of the cities using that zipcode. The default city is selected with the OK button having focus. I would store every part of the address together for a given address. In our new system, we have the similar set up as above, but we only keep the ZipID (ID, for the city, state and Zip) with the address. The extra joins needed now are a bit of a pita, so I could imagine how much more it would be to use a junction table containing an CSZid, CityID, Stid & ZipID. I guess it all boils down to what level of normalization do you want to go? 3rd, 4th? Oh, btw, are you only dealing with US addresses or INTL addresses too? Because that will add some twists too ;) David -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com]On Behalf Of John Clark Sent: Thursday, March 11, 2004 12:02 PM To: accessd at databaseadvisors.com Subject: [AccessD] question on normalization quick question: I have a program that will be populated with a 'regional' group of people--this meaning that everyone's address will be within this county. So I am thinking that I can speed up entry, by using a drop-down for zip codes and filling the town name from that. My question is, would it be proper to have a separate table for town and another for zip code, even though zip code would be a single field table? The town table would have three tables, with one being a link to the Zip Code table, and the Zip Code table would have a single field--"Zip". Thanks John W Clark -- _______________________________________________ AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com