[Year 12 IT Apps] Database relationships

[Lisa Imms]

Hi Mark,
 
Firstly, thanks for the resource :-)
 
I hate to even contemplate disagreeing with you as my ITA class and I regard you as the ITA font-of-all-knowledge, but I will try this anyway.....
 
Your example for one-to-one: "E.g. an employee's department data in one table matches a corresponding department in another table, allowing data relating to that department to be fetched."
 
Wouldn't this be a one to many relationship? Even the line you have joining them has the 'many feathers' at the employees table? Although each employee can belong to only one department, each department can (and will) have multiple employees? So it is actually a one to many relationship? 
 
Am I correct in assuming that a well organised database would not have any one-to-one relationships? The two tables in a one-to-one relationship could/should just be merged into one table? 
 
Lisa Bairstow
St Mary's Coptic Orthodox College

________________________________

From: itapps-bounces at edulists.com.au on behalf of Mark Kelly
Sent: Wed 7/23/2008 2:24 PM
To: Year 12 IT Applications Teachers' Mailing List
Subject: [Year 12 IT Apps] Database relationships



Hi all.  It's been mighty quiet here for a while.  To perk things up,
here's a little revision for database relationships (1-1, 1-many,
many-many) that may or may not be useful.

Cheers
Mark

--
Mark Kelly
Manager - Information Systems
McKinnon Secondary College
McKinnon Rd McKinnon 3204, Victoria, Australia
Direct line / Voicemail: 8520 9085
School Phone +613 8520 9000
School Fax +613 95789253
kel AT mckinnonsc.vic.edu.au

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