>-----Original Message----- >From: Martijn Tonies [mailto:[EMAIL PROTECTED] >Sent: Thursday, July 31, 2008 10:32 AM >To: mysql@lists.mysql.com >Subject: Re: SET vs. ENUM > >Jerry, > >> >> Other than the fact that an ENUM can have many more values than a >SET, >> >is >> >> there any particular reason to choose one over the other? >> > >> >Well, they are -different things- ... >> > >> >SETs shouldn't be used at all, IMO. >> > >> [JS] Why? > >It goes against normalizing your data, that's why. > >You cannot query them properly, that's why (just check the archives of >this >list). > >You cannot add a possible value (same goes for ENUM) without a DDL >statement, so "data" is intertwined with "metadata", which is bad. > >The metadata is not portable to other systems (neither is ENUM). > >> >ENUM can be somewhat useful, I guess. > > >Need more reasons? :-) > [JS] No, you've made several good points. My reasoning is that inexperienced folks using this table through MS Access don't generally understand enough about database design to create the necessary JOINs to do it right. Perhaps the trade-off is a bad one.
>Martijn Tonies >Database Workbench - tool for InterBase, Firebird, MySQL, NexusDB, >Oracle & >MS SQL Server >Upscene Productions >http://www.upscene.com >My thoughts: >http://blog.upscene.com/martijn/ >Database development questions? Check the forum! >http://www.databasedevelopmentforum.com > > >-- >MySQL General Mailing List >For list archives: http://lists.mysql.com/mysql >To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] >infoshop.com -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
