Three tables in a one-to-one chain valid?

amezick · **Joined:** Mon Nov 03, 2003 11:48 pm **Posts:** 29

I have three tables:
parent, child, grandchild. The Parent has a 1to1 to Child. The Child has a 1to1 to Grandchild. So all three tables share the same primary key using Identity generation on the Parent and foreign generation on Child and Grandchild. Is this configuration possible within hibernate. I know it seems silly, but this structure makes sense for the types of data we are dealing with. (Esp for using lazy)
--Angus

emmanuel · **Posted:** Mon Jun 28, 2004 1:34 pm

I should work and it make sense. Be sure to understand http://www.hibernate.org/162.html however

amezick · **Joined:** Mon Nov 03, 2003 11:48 pm **Posts:** 29

I have read this page. To get the save and delete to work I have:
parent:

Code:

   <class
        name="org.guidestar.uk.fin.hibernate.FinHeader"
        table="fin_header"
        proxy="org.guidestar.uk.fin.hibernate.FinHeader"
        dynamic-update="false"
        dynamic-insert="false"
    >

        <id
            name="tarId"
            column="tar_id"
            type="java.lang.Integer"
            unsaved-value="null"
        >
            <generator class="identity">
            </generator>
        </id>

        <one-to-one
            name="finBalSheetAsset"
            class="org.guidestar.uk.fin.hibernate.FinBalSheetAsset"
            cascade="all"
            outer-join="false"
            constrained="false"
        />

Child:

Code:

   <class
        name="org.guidestar.uk.fin.hibernate.FinBalSheetAsset"
        table="fin_bal_sheet_assets"
        proxy="org.guidestar.uk.fin.hibernate.FinBalSheetAsset"
        dynamic-update="false"
        dynamic-insert="false"
    >

        <id
            name="tarId"
            column="tar_id"
            type="java.lang.Integer"
        >
            <generator class="foreign">
                <param name="property">finHeader</param>
            </generator>
        </id>
        <one-to-one
            name="finHeader"
            class="org.guidestar.uk.fin.hibernate.FinHeader"
            cascade="none"
            outer-join="false"
            constrained="true"
        />

Right now I can do the full select, insert, update, delete.
Are you saying I need to set the constrained on the parent to true as well? When I tried this I get an error:

Code:

net.sf.hibernate.PropertyValueException: not-null property references a null or transient value: org.guidestar.uk.fin.hibernate.FinBalSheetAsset.finHeader
   at net.sf.hibernate.impl.SessionImpl.checkNullability(SessionImpl.java:1276)
   at net.sf.hibernate.impl.SessionImpl.doDelete(SessionImpl.java:1244)
   at net.sf.hibernate.impl.SessionImpl.delete(SessionImpl.java:1172)
   at net.sf.hibernate.engine.Cascades$1.cascade(Cascades.java:61)
   at net.sf.hibernate.engine.Cascades.cascade(Cascades.java:436)
   at net.sf.hibernate.engine.Cascades.cascade(Cascades.java:503)
   at net.sf.hibernate.engine.Cascades.cascade(Cascades.java:482)
   at net.sf.hibernate.impl.SessionImpl.doDelete(SessionImpl.java:1260)
   at net.sf.hibernate.impl.SessionImpl.delete(SessionImpl.java:1172)
   at org.guidestar.database.dm.HibernateDataManager.deleteObj(HibernateDataManager.java:304)

I would love to see a simple example for 1to1, lazy loaded, identy generation on parent, using the parent's key on the child.

amezick · **Joined:** Mon Nov 03, 2003 11:48 pm **Posts:** 29

forgot to mention that, yes, I do have the key column set to not-null
--Angus

JavaJohnson · **Joined:** Mon Jun 07, 2004 9:08 am **Posts:** 5

I would also like to see an example of creating a new instance of a class where there is a lazy loaded 1-1 with parent key generation.

Is this even possible?