referential integrity, my friend. it basically is another layer of protection for dumb mistakes. it prevents you from removing a row in a table that is used by another table. it helps prevent orphan records.
tw On 6/2/05, Matthew Small <[EMAIL PROTECTED]> wrote: > For the past 8 years I've been working with SQL, I've never really > understood how to use the relational diagrams that use primary and foreign > keys. I just recently found the diagram tool in SQL and I like it for > laying out my new databases. However, even though I understand the > concepts, I don't really see the use of connecting the tables together in > these diagrams, of declaring the foreign and primary keys in these things. > In my programming, I know which tables are related to other tables, but why > is it good to tell the db what these relationships are? > > > > Thanks, > > > > Matthew Small > > Web Developer > > American City Business Journals > > 704-973-1045 > > [EMAIL PROTECTED] > > > > > > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Find out how CFTicket can increase your company's customer support efficiency by 100% http://www.houseoffusion.com/banners/view.cfm?bannerid=49 Message: http://www.houseoffusion.com/lists.cfm/link=i:5:159467 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/5 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:5 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.5 Donations & Support: http://www.houseoffusion.com/tiny.cfm/54
