Hello,

I'm trying to map the following Object relations:
AssemblyType - contains a Collection of Assemblies
Assembly - contains a map with the key bieng of type PiecePart and the value being an Integer representing the quantity of said part.

I wish to perform a "save" on the AssemblyType and have it cascade through to the PiecePart level. Relavent bits of my mapping files:

AssemblyType.hbm.xml:
-----------------------------
<set name="assemblyList" inverse="true" lazy="false"
cascade="persist,merge,save-update,delete-orphan">
<key column="assemblyTypeID"/>
<one-to-many class="Assembly"/>
</set>


Assembly.hbm.xml:
-----------------------
<many-to-one name="AssemblyType" column="assemblyTypeID" class="AssemblyType"/>

<map name="piecePartMap" table="AssemblyPieceParts" lazy="false"
cascade="persist,merge,save-update">
<key column="assemblyID"/>
<map-key-many-to-many class="PiecePart" column="partID"/>
<element type="int" column="quantity"/>
</map>


PiecePart.hbm.xml: (nothing special here)
----------------------
<property name="partNumber" type="string" unique="true" not-null="true"/>
<property name="description" type="string" not-null="true"/>


These mapping files build the tables I wish and work *if* the PieceParts are already defined, but generate a TransientObjectException if a PiecePart is not yet defined. I was able to hack a "solution" to force a save of the PiecePart by modifying Assembly.hbm.xml to include:

<set name="pieceParts" table="PiecePartHack" lazy="false"
cascade="persist,merge,save-update">
<meta attribute="description">
A (hopefully-temporary) hack to force hibernate to persist parts
before creating the map table "piecePartMap"
</meta>
<key column="piecePartID"/>
<many-to-many class="PiecePart"/>
</set>

This cobbled hack forces me to keep an extra Collection on the Java side and create an extra table on the db side -- not ideal.

I'm far from an expert (which is perhaps obvious), but have read the forum, The Book, and anything else I can get my hands on -- so if the solution should be obvious, please blame ignorance rather than laziness.

thanx,

-don.

I should have noted that I'm using Hibernate3.

thanx,

-don.

i know this is a cheap trick to get the post back to the front, but really -- does *anyone* have *any* suggestions?

thanx,

-don.

Yes I noticed the "cascade save" wouldn't save map key objects before main object so you get a transient object error. I had to call .save() on map key object first. This can be inconvenient.