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From:US Data Export Date:November 14 2008 3:50pm
Subject:RE: normalised designs: customer database
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>-----Original Message-----
>From: Martijn Tonies [mailto:m.tonies@stripped]
>Sent: Friday, November 14, 2008 10:44 AM
>To: 'mysql'
>Subject: Re: normalised designs: customer database
>
>> >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.
>
[JS] I understand your point, but in real life that can lead to a user
seeing ugly, incomprehensible error messages.

What I do, in many cases, is provide a dropdown whose values are populated
from a table of possible values. I suppose you could use that same table to
enforce foreign key constraints as well, but isn't the effect the same?




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