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Re: Multiple databases an EOModel.
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Re: Multiple databases an EOModel.

  • Subject: Re: Multiple databases an EOModel.
  • From: Ramsey Gurley <email@hidden>
  • Date: Thu, 20 Dec 2012 17:40:35 -0700
You lose FK constraints that way too. I would not break up the database if you need relationships between the models. That includes in the future. 

Even if you don't have relationships, think about what happens when a client with more than one enterprise wants to move data between the two databases or possibly merge them? PK collisions, fk collisions. Nightmare code trying to follow relationships and reassign IDs.

Worst of all, I can imagine a day when the client will dream up some reason why they need to relate data between DB1 and DB2. Then you are truly pooched. No siree, I'd simply add a column to the model indicating which enterprise the data belongs to and put everything in one database. Otherwise, I think you're setting yourself up for a world of hurt.

Ramsey

On Dec 20, 2012, at 5:01 PM, Michael Gargano wrote:

yes, I'm doing that now.   just be aware that cross db joins are a b*tch.  if there are to many relations to join across you will quickly hit limitations with IN clauses (which will be your best friend).  unless someone else has come up with something more clever than what I'm doing

-Mike

On Dec 20, 2012, at 6:45 PM, Miguel Torres <email@hidden> wrote:

Hi list,

We are developing an ERP application.
We want to use the following approach:

One database to storage users, access control rules, application configuration and an enterprises catalog.

For each enterprise we want to set up a different database. 

For example: One ERP controlling information of two enterprises would need three databases:
  • ApplicationDatabase
  • EnterpriseOneDatabase
  • EnterpriseTwoDatabase

We are doing this because we believe this is more efficient in the long term with clients that have more than one enterprise.

We have two Data base Models in the application

  • ErpApplicatioEOModel
  • ErpEnterpriseEOModel

The main page is a Login form where the user selects the Enterprise she wants to work with. After the user logins successfully we want to set the database connection information in the ErpEnterpriseEOModel.

Is that possible?


Thanks in advanced.

Saludos, Miguel Torres.

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  • Follow-Ups:
    • Re: Multiple databases an EOModel.
      • From: Larry Mills-Gahl <email@hidden>
    • Re: Multiple databases an EOModel.
      • From: Miguel Torres <email@hidden>
References: 
 >Multiple databases an EOModel. (From: Miguel Torres <email@hidden>)
 >Re: Multiple databases an EOModel. (From: Michael Gargano <email@hidden>)

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