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From:Martijn Tonies Date:November 14 2008 3:44pm
Subject:Re: normalised designs: customer database
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> >3) create the customer table with a FK for people and a FK for
> >companies, and decide on the customer type in the application based on
> >the presence of that key
> >
> [JS] I'm not sure why you need a foreign key. Surely you won't be entering
> customers using the MySQL CLI client on a routine basis, so your user
> interface could (and should) be responsible for checking the data.

Ehm, no, if it's possible, put the constraints -on the database- ... Never
ever rely on the application alone to enforce data consistency.

> If you really feel the need to constrain the data, define the column as a
> set.

Martijn Tonies
Database Workbench - tool for InterBase, Firebird, MySQL, NexusDB, Sybase
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Upscene Productions
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http://blog.upscene.com/martijn/
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Thread
normalised designs: customer databasemetastable14 Nov
  • Re: normalised designs: customer databaseMark Goodge14 Nov
    • Re: normalised designs: customer databaseMr. Shawn H. Corey14 Nov
      • Re: normalised designs: customer databasemetastable14 Nov
  • RE: normalised designs: customer databaseJerry Schwartz14 Nov
  • Re: normalised designs: customer databaseJujitsu Lizard14 Nov
  • Re: normalised designs: customer databaseMartijn Tonies14 Nov
    • RE: normalised designs: customer databaseUS Data Export14 Nov
      • Re: normalised designs: customer databasemetastable14 Nov
  • Re: normalised designs: customer databaseMartijn Tonies14 Nov
    • Re: normalised designs: customer databaseJujitsu Lizard14 Nov
      • Re: normalised designs: customer databasePeter Brawley14 Nov
  • Re: normalised designs: customer databaseMartijn Tonies14 Nov
  • Re: normalised designs: customer databaseMartijn Tonies14 Nov
  • Re: normalised designs: customer databaseMartijn Tonies14 Nov
    • Re: normalised designs: customer databaseJujitsu Lizard14 Nov
      • Re: normalised designs: customer databasemetastable14 Nov
    • Re: normalised designs: customer databasemetastable15 Nov
      • Re: normalised designs: customer databaseJujitsu Lizard15 Nov
        • Re: normalised designs: customer databasemetastable16 Nov
          • RE: normalised designs: customer databaseJerry Schwartz17 Nov
            • Re: normalised designs: customer databasemetastable17 Nov
  • Re: normalised designs: customer databaseBill newton14 Nov
  • Re: normalised designs: customer databaseMartijn Tonies17 Nov
  • Re: normalised designs: customer databaseMartijn Tonies17 Nov
  • Re: normalised designs: customer databaseMartijn Tonies17 Nov
    • RE: normalised designs: customer databaseUS Data Export17 Nov
  • Re: normalised designs: customer databaseMartijn Tonies17 Nov