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Re: Help with this db design
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Re: Help with this db design


  • Subject: Re: Help with this db design
  • From: Guido Neitzer <email@hidden>
  • Date: Sun, 23 Mar 2008 09:31:23 -0600

On 23.03.2008, at 01:11, Art Isbell wrote:

So add a unique constraint on the database level (to be safe) and check for this condition in code (validateForSave) before saving to the database.

Just use a compound primary key like a join entity, both being propagated from the entities in the many-to-many relationship. This applies the desired constraint without needing to actually add an explicit constraint to the DB.

Hmmm. I actually don't like that for entities that are more than just "join entities" with only two keys. Whether it works or not, I just don't like the modeling. But that's my own taste, do what works for you.


cug

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References: 
 >Help with this db design (From: Gustavo Pizano <email@hidden>)
 >Re: Help with this db design (From: Jean-François Veillette <email@hidden>)
 >Re: Help with this db design (From: Gustavo Pizano <email@hidden>)
 >Re: Help with this db design (From: Jean-François Veillette <email@hidden>)
 >Re: Help with this db design (From: Gustavo Pizano <email@hidden>)
 >Re: Help with this db design (From: Guido Neitzer <email@hidden>)
 >Re: Help with this db design (From: Gustavo Pizano <email@hidden>)
 >Re: Help with this db design (From: Guido Neitzer <email@hidden>)
 >Re: Help with this db design (From: Gustavo Pizano <email@hidden>)
 >Re: Help with this db design (From: Guido Neitzer <email@hidden>)
 >Re: Help with this db design (From: Art Isbell <email@hidden>)

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