Re: How to create Meaningful Primary Keys?

From: Pierre Lavignotte (pierre.lavignott..mail.com)
Date: Mon Feb 02 2009 - 08:28:39 EST

  • Next message: Andrus Adamchik: "Re: How to create Meaningful Primary Keys?"

    I don't think his question is about sequence usage but about selecting rows
    with specific PK values...

    Cordialement,
    Pierre Lavignotte
    Ingénieur Conception & Développement
    http://pierre.lavignotte.googlepages.com

    On Mon, Feb 2, 2009 at 2:25 PM, Alessio Giovanni Baroni <
    alessiogiovanni.baron..mail.com> wrote:

    > It's all ok. But, you are sure that in Entity screen, you are selected
    > "Custom Sequence" on the "PK Generation Strategy"?
    > If you do it, AND you add a filed relative to a pk column, you can handling
    > the keys, without the cayenne's control.
    >
    > Hi.
    >
    >
    > 2009/2/2 Νίκος Παράσχου <niparas..mail.com>
    >
    > > 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 <niparas..mail.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
    > > > >
    > > > >
    > >
    > >
    >



    This archive was generated by hypermail 2.0.0 : Mon Feb 02 2009 - 08:29:22 EST