Re: First time inheritance attempt

From: Michael Gentry (mgentr..asslight.net)
Date: Thu Sep 24 2009 - 13:46:02 EDT

  • Next message: Dave Lamy: "Re: First time inheritance attempt"

    You are trying to do multiple-table inheritance?

    Unless I'm mistaken, I don't believe that has been implemented yet.
    Cayenne can do in-table inheritance using a discriminator column.

    On Thu, Sep 24, 2009 at 1:10 PM, Dave Lamy <davelam..mail.com> wrote:
    > Hey guys--
    >
    > I'm attempting to model some inheritance for the first time and it's not
    > working yet.  Here's my situation:
    >
    > My model is to have a non-abstract parent class->table and then
    > subclass->tables like so:
    >
    > First I should doublecheck to make sure my mapping XML looks OK:
    >
    >    <db-entity name="ASSET_CONTENT">
    >        ...
    >        <db-attribute name="CONTENT_TYPE" type="VARCHAR" length="50"/>
    >        <db-attribute name="ID" type="INTEGER" isPrimaryKey="true"
    > isGenerated="true" isMandatory="true"/>
    >        ...
    >    </db-entity>
    >    <db-entity name="IMAGE_ASSET_CONTENT">
    >        <db-attribute name="HEIGHT" type="INTEGER"/>
    >        <db-attribute name="ID" type="INTEGER" isPrimaryKey="true"
    > isMandatory="true"/>
    >        <db-attribute name="WIDTH" type="INTEGER"/>
    >    </db-entity>
    >    <obj-entity name="AssetContent"
    > className="com.routeto1.asset.filesystem.AssetContent"
    > lock-type="optimistic" dbEntityName="ASSET_CONTENT"
    > superClassName="com.routeto1.data.impl.DynamicDataObject">
    >        <obj-attribute name="contentType" type="java.lang.String"
    > db-attribute-path="CONTENT_TYPE"/>
    >         ...
    >        <pre-persist method-name="prePersist"/>
    >    </obj-entity>
    >    <obj-entity name="ImageAssetContent" superEntityName="AssetContent"
    > className="com.routeto1.asset.filesystem.ImageAssetContent"
    > lock-type="optimistic" dbEntityName="IMAGE_ASSET_CONTENT">
    >        <qualifier><![CDATA[contentType = "IMAGE"]]></qualifier>
    >        <obj-attribute name="height" type="java.lang.Integer"
    > db-attribute-path="HEIGHT"/>
    >        <obj-attribute name="width" type="java.lang.Integer"
    > db-attribute-path="WIDTH"/>
    >    </obj-entity>
    >
    > Not sure if I need to provide you any more than that.  Cayenne accepts the
    > config fine, but when I create a new ImageAssetContent and save it, Cayenne
    > only saves to the IMAGE_ASSET_CONTENT  table:
    >
    > 2009-09-24 10:30:53,602 INFO [org.apache.cayenne.access.QueryLogger] -
    > <INSERT INTO IMAGE_ASSET_CONTENT (HEIGHT, ID, WIDTH) VALUES (?, ?, ?)>
    > 2009-09-24 10:30:53,656 INFO [org.apache.cayenne.access.QueryLogger] -
    > <[batch bind: 1->HEIGHT:440, 2->ID:220, 3->WIDTH:495]>
    >
    > I've confirmed that there is data in the object that should be getting saved
    > to the ASSET_CONTENT table but is not.
    >
    > What's also interesting is that it is pulling an auto PK value (this is
    > running on a Derby DB for testing):
    >
    > 2009-09-24 10:30:53,258 INFO [org.apache.cayenne.access.QueryLogger] -
    > <SELECT NEXT_ID FROM AUTO_PK_SUPPORT WHERE TABLE_NAME = ? FOR UPDATE [bind:
    > 1:'IMAGE_ASSET_CONTENT']>
    >
    > Not so interesting that it's pulling one, but for IMAGE_ASSET_CONTENT?   I'd
    > assume it would be pulling for ASSET_CONTENT and reusing that ID in both the
    > parent and child tables.
    >
    > Am I missing something really basic?
    >
    > I've tested this on 3.0 M5 and M6 with same results.
    >
    > Dave
    >



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