Re: Select By ID

From: Pierre Lavignotte (pierre.lavignott..mail.com)
Date: Tue Dec 09 2008 - 11:57:40 EST

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    Hi,

    By default, Cayenne Modeler hides the primary key information of your object
    entities.
    You should look at the DataObjectUtils class that provide some very usefull
    methods to access primary key of persistent objects and to get persistent
    objects from their primary key.

    For ex. if you use interger primary keys :
    DataObject org.apache.cayenne.DataObjectUtils.objectForPK(ObjectContext
    context, Class dataObjectClass, int pk)
    int org.apache.cayenne.DataObjectUtils.intPKForObject(Persistent dataObject)

    With that, you can get the ID of any persistent object and get an object by
    its ID.

    To delete an object, you don't have to code any SQL query, just use the API
    from the DataContext class.

    Pierre

    On Tue, Dec 9, 2008 at 5:49 PM, Filipe Costa <nevco..mail.com> wrote:

    > Hi all,
    >
    > I'm creating a new project and I chosed to use Cayenne 2.4.
    >
    > The thing is that I want to make a simple "Select By Id" query (auto
    > generated id), but it seems it is not possible! Can anyone help me?
    >
    > If there are no way of selecting by an Id, how you can make basic
    > functionality like a table where you can delete some specific row? "Delete
    > USER where name = 'name'" is not a good option... neither creating a new
    > key
    > column to do this.
    >
    > Thanks in advance.
    >
    > Cheers
    >

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



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