Updating Obj in Set of 1 to Many not updating

purcell5 · **Joined:** Thu Aug 21, 2008 4:33 pm **Posts:** 2

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Hibernate version: 313

I have 2 simple Entity tables.

TableA:
id (PK)
name

Table B:
id (PK)
data bytes[]
afk (FK) FK to Table A.

I have them both mapped as entities and there is a 1 to many from A to B.

I create A, then create B, then add B to A and persist. There is a cascade from A to B. This works great.

Problem is here:
In a later unit of work, I retrieve A, iterate over set, update the data bytes[] in this example with new data and save A.

Problem is the data never gets persisted. If I retrieve A, and loop around the set and look at the data bytes[], the data was what was originally put into the column. It never gets updated.

So I have a set of entities, that have cascades set, I update the data, and persist, but data does not get updated.

Mappings:
a, then B

Code:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
    "-//Hibernate/Hibernate Mapping DTD//EN"
    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >

<hibernate-mapping>

    <class name="comppfi" 
    table="FILE">
        <id name="Id" type="long" column="FILE_ID">
            <generator class="sequence">
                <param name="sequence">FILE_SEQ</param>
            </generator>
        </id>

        <set
            name="myBs"
            cascade="save-update" 
        >
            <key column="x_FILE_ID" />
            <one-to-many class="com.BBBB"/>  
        </set>  
        
  
</hibernate-mapping>



<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
    "-//Hibernate/Hibernate Mapping DTD//EN"
    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >

<hibernate-mapping>
    <class
        name="PaymentProcessFileDataImpl"
        dynamic-insert="true"
        dynamic-update="true"
        table="FILE_DATA">
        <id name="id" type="long"
            column="DATA_ID">
            <generator class="sequence">
                <param name="sequence">DATA_ID_SEQ</param>
            </generator>
        </id>
        
        <property 
            name="mydata" 
            column="MY_DATA"
            type="blob" 
            not-null="true" />

         
        <many-to-one
            name="myBBBB" 
            class="com.BBBB" 
        >
            <column name="x_FILE_ID" 
                not-null="true" />
        </many-to-one>
            
    </class>
    
</hibernate-mapping>

Workflow is, create A, add B, persist A, using Transitive persistance have B saved. This works great.

Later on, fetch A, update B and persist A. B is not getting updated.

Thanks

hlfsousa · **Posted:** Fri Aug 22, 2008 8:14 am

Hi,

Your basic logic seems OK, but I one expression stands out here:

Quote:

Later on, fetch A, update B and persist A. B is not getting updated.

Hibernate (and more recently JPA in general) works by checking for changes in attached objects. So if you fetch A and update B (by calling B's setter methods), you should only call flush() on your Session or EntityManager.

Try showing the SQL queries and check the result of flushing right after updating B's attributes. You should see some update query on B's table.

Besides, cascading would be negatively affected if you set a new collection to the one-to-many property of A.

Show us some code if this does not clear up things, ok?