Hi,

I have a parent / child object (basket and basket item). I have a single row in the BasketItem table. When I retrieve the parent basket instance, the BasketItems list is populated with 2 rows:
1) the single basket item
2) a null entry.

my question is why is the null value in the list rather than just the single entry.

Hibernate 3.0.5, MySQL 4.0.16

hibernate config entries:

from Baket.hbm.xml
<list name="basketItems" lazy="false" outer-join="false" inverse="true" cascade="delete">
<key foreign-key="BASKET_ITEM_BASKET_FKC">
<column name="BASKET_FK"/>
</key>
<index column="id"/>
<one-to-many class="com.codeczar.commerce.basket.BasketItem"/>
</list>

from BasketItem.hbm.xml
<hibernate-mapping default-cascade="none">
<class name="com.codeczar.commerce.basket.BasketItem" table="BASKET_ITEM" dynamic-insert="false" dynamic-update="false">
<id name="id" type="java.lang.Integer" unsaved-value="null">
<column name="ID" sql-type="INTEGER"/>
<generator class="native">
</generator>
</id>
............ snip
<many-to-one name="basket" class="com.codeczar.commerce.basket.Basket" outer-join="auto" foreign-key="BASKET_ITEM_BASKET_FKC">
<column name="BASKET_FK" not-null="true" sql-type="INTEGER"/>
</many-to-one>
</class>
</hibernate-mapping>

Here's the debug which confirms a single basket item returned

Hibernate: select basketitem0_.BASKET_FK as BASKET4_1_, basketitem0_.ID as ID1_, basketitem0_.id as id1_, basketitem0_.ID as ID0_, basketitem0_.QUANTITY as QUANTITY7_0_, basketitem0_.PRODUCT_FK as PRODUCT3_7_0_, basketitem0_.BASKET_FK as BASKET4_7_0_ from BASKET_ITEM basketitem0_ where basketitem0_.BASKET_FK=?
[AbstractBatcher] preparing statement
[xapool] StandardXAConnectionHandle:prepareStatement tx==null
[jta] threadTx.get= java.lang.ThreadLocal@13e754f
[jta] Transaction ret= null
[xapool] StandardXAConnectionHandle:prepareStatement (no transaction found)
[xapool] StandardXAPreparedStatement: Create an XAPreparedStatement with sql='select basketitem0_.BASKET_FK as BASKET4_1_, basketitem0_.ID as ID1_, basketitem0_.id as id1_, basketitem0_.ID as ID0_, basketitem0_.QUANTITY as QUANTITY7_0_, basketitem0_.PRODUCT_FK as PRODUCT3_7_0_, basketitem0_.BASKET_FK as BASKET4_7_0_ from BASKET_ITEM basketitem0_ where basketitem0_.BASKET_FK=?'
[xapool] StandardXAConnectionHandle:checkPreparedCache object is *NOT* found
[xapool] StandardConnectionHandle:createPreparedStatement type ='0'
[xapool] StandardXAConnectionHandle:checkPreparedCache pstmt='com.mysql.jdbc.PreparedStatement@1304043: select basketitem0_.BASKET_FK as BASKET4_1_, basketitem0_.ID as ID1_, basketitem0_.id as id1_, basketitem0_.ID as ID0_, basketitem0_.QUANTITY as QUANTITY7_0_, basketitem0_.PRODUCT_FK as PRODUCT3_7_0_, basketitem0_.BASKET_FK as BASKET4_7_0_ from BASKET_ITEM basketitem0_ where basketitem0_.BASKET_FK=** NOT SPECIFIED **'
[IntegerType] binding '1' to parameter: 1
[AbstractBatcher] about to open ResultSet (open ResultSets: 0, globally: 0)
[Loader] result set contains (possibly empty) collection: [com.codeczar.commerce.basket.Basket.basketItems#1]
[CollectionLoadContext] uninitialized collection: initializing
[Loader] processing result set
[Loader] result set row: 0
[IntegerType] returning '1' as column: ID0_
[Loader] result row: EntityKey[com.codeczar.commerce.basket.BasketItem#1]
[Loader] Initializing object from ResultSet: [com.codeczar.commerce.basket.BasketItem#1]
[BasicEntityPersister] Hydrating entity: [com.codeczar.commerce.basket.BasketItem#1]
[IntegerType] returning '1' as column: QUANTITY7_0_
[IntegerType] returning '1' as column: PRODUCT3_7_0_
[IntegerType] returning '1' as column: BASKET4_7_0_
[IntegerType] returning '1' as column: BASKET4_1_
[Loader] found row of collection: [com.codeczar.commerce.basket.Basket.basketItems#1]
[CollectionLoadContext] reading row
[IntegerType] returning '1' as column: ID1_
[DefaultLoadEventListener] loading entity: [com.codeczar.commerce.basket.BasketItem#1]
[DefaultLoadEventListener] attempting to resolve: [com.codeczar.commerce.basket.BasketItem#1]
[DefaultLoadEventListener] resolved object in session cache: [com.codeczar.commerce.basket.BasketItem#1]
[IntegerType] returning '1' as column: id1_
[Loader] done processing result set (1 rows)

To confirm that a list with two rows is passed to the setBasketItems method, I included a debug statement with a stack.

[Basket] setting basketItems size '2' [null, com.codeczar.commerce.basket.BasketItem................]
java.lang.Exception:
at com.codeczar.commerce.basket.Basket.setBasketItems(Basket.java:69)
at com.codeczar.commerce.basket.Basket$$BulkBeanByCGLIB$$c166c88f.setPropertyValues(<generated>)
at org.hibernate.tuple.PojoTuplizer.setPropertyValuesWithOptimizer(PojoTuplizer.java:200)
at org.hibernate.tuple.PojoTuplizer.setPropertyValues(PojoTuplizer.java:173)
at org.hibernate.persister.entity.BasicEntityPersister.setPropertyValues(BasicEntityPersister.java:2919)
at org.hibernate.engine.TwoPhaseLoad.initializeEntity(TwoPhaseLoad.java:113)
at org.hibernate.loader.Loader.initializeEntitiesAndCollections(Loader.java:530)
at org.hibernate.loader.Loader.doQuery(Loader.java:436)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:218)
at org.hibernate.loader.Loader.loadEntity(Loader.java:1345)
at org.hibernate.loader.entity.EntityLoader.load(EntityLoader.java:116)
at org.hibernate.loader.entity.EntityLoader.load(EntityLoader.java:101)
at org.hibernate.persister.entity.BasicEntityPersister.load(BasicEntityPersister.java:2471)
at org.hibernate.event.def.DefaultLoadEventListener.loadFromDatasource(DefaultLoadEventListener.java:351)
at org.hibernate.event.def.DefaultLoadEventListener.doLoad(DefaultLoadEventListener.java:332)
at org.hibernate.event.def.DefaultLoadEventListener.load(DefaultLoadEventListener.java:113)
at org.hibernate.event.def.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:167)
at org.hibernate.event.def.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:79)
at org.hibernate.impl.SessionImpl.load(SessionImpl.java:592)


Any help greatly appreciated, completely stuck here.

cheers
Nathan