Dependent property and cascading delete in visual designer

2 posts, 0 answers
  1. test
    test avatar
    27 posts
    Member since:
    Feb 2008

    Posted 23 Nov 2010 Link to this post

    Hi,

    I've a problem using the dependent property. I'm not using the ORM Classic but visual designer.

    I want to delete a parent when I delete its child

    I've a metaclass "Photography" defined like this :
    PhotographyId
    Name
    FileId
    File

    And a metaclass "File" defined like this :
    FileId
    Url
    Photographies

    And an association between this 2 metaclasses : PhotographyHasFile, SourceMultiplicity : One, TargetMultiplicity : ZeroOne.

    When i look to the relationships for the metaclass "Photography", I see my association between  my 2 metaclasses and check "managed" and "dependent" check boxes.

    In my code, I load a photography using a fetchstrategy to get file informations too. When I do "dbcontext.delete(oPhotography)" I'm expecting the photography and its file are deleted but only the photography is deleted.

    Could you explain why ? And how to do cascading delete with the new model of openacces.

    Thanks for your help.


  2. Petko_I
    Admin
    Petko_I avatar
    184 posts

    Posted 26 Nov 2010 Link to this post

    Hi test,

    As far as we can see, you have defined a relation between Photography and File which you would like to be one-to-one. OpenAccess currently does not support one-to-one associations and here is where the confusion comes. Under the cover the relationship between File and Photography is one-to-many. The Photography entity has a reference to a File, but the File entity has a collection of references (Photographies). The cascading delete will work if you delete a File - then all related Photographies will be deleted as well. If you reverse the relationship and let the Photography entity have a collection of Files and File has a property PhotographyID which relates to the identity of a Photography you will be able to implement a cascading delete on the part of the Photography.

    Feel free to contact us, should you need any further assistance.

    Best wishes,
    Petko_I
    the Telerik team
    Accelerate your learning with industry's first Telerik OpenAccess ORM SDK. Download today.
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