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From Νίκος Παράσχου <nipar...@gmail.com>
Subject Re: How to create Meaningful Primary Keys?
Date Mon, 02 Feb 2009 13:14:45 GMT
First of all thank you for your replies.

I have the following table:

Vehicle (
       plate_num CHAR(10) NOT NULL,
       mixed_weight DOUBLE PRECISION NOT NULL,
       type CHAR(30) NOT NULL,
       manufacturer CHAR(20),
       PRIMARY KEY (plate_num)
)

In Cayenne Modeller I have the dbEntity "vehicle" with all the above
attributes (plate_num is check as PK). There is also the objEntity
"Vehicle" with all the above attributes except the PK (plate_num).

I want to select the type of the vehicle with plate_num = "AHZ-4141".

Could you please post some code samples? I have tried so many things
(with DataObjectUtils too) but still no success.

Thank you,
Nikos

Στις 02-02-2009, ημέρα Δευ, και ώρα 12:49 +0100, ο/η Pierre Lavignotte
έγραψε:
> Hi Nikos,
> 
> If you need PK for all your tables, then maybe you need to generate them.
> But if you only need to use them for a couple tables then you should look at
> DataObjectUtils class.
> 
> 
> Cheers,
> Pierre
> 
> Cordialement,
> Pierre Lavignotte
> Ingénieur Conception & Développement
> http://pierre.lavignotte.googlepages.com
> 
> 
> On Mon, Feb 2, 2009 at 12:35 PM, Νίκος Παράσχου <niparasc@gmail.com>
wrote:
> 
> > Hello,
> >
> > It is the first time I am using cayenne and I have some questions
> > regarding the primary keys.
> >
> > What I want to do is select some rows of a table where the PK has a
> > specific value. The problem is I can't access the PK. I can specify
> > qualifiers only with the non-PK columns. The PKs I am using have some
> > meaning (they are not just numbers) so it is very important to be able
> > to use them.
> >
> > How can I add the PK to the fields of the Object Entities?
> >
> > In this page http://cayenne.apache.org/doc20/primary-key-generation.html
> > the answer is to create a Meaningful Primary Key.
> >
> > How can I create Meaningful Primary Keys?
> >
> > Are there any security issues when using Meaningful Primary Keys?
> >
> > Thank you for your time,
> > Nikos
> >
> >


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