Major Description
> On 14/06/2005 12:42 PM, Matt Hogstrom wrote:
>
>>I have a typical bean sequence where there is an Order and a number of Order Lines. (1 ... many) The OrderEnt is created from a Session bean coincidentally named OrderSes. The OrderEnt then in ejbPostCreate creates the appropriate OrderLines. Here is the code from OrderEnt:
>>
>> public void ejbPostCreate(OrderDataBean odb, boolean deferred)
>> throws CreateException {
>>
>>
> <snip>
>
>>Depending on the situation one of the above orderLineHome.create methods is invoked. So far, so good.
>>
>>In the OrderLineEnt.create method things go a bit wrong. Here is the stack trace:
>>
>>Caused by: javax.ejb.EJBException: cmp-field [orderId] is read-only.
>> at org.tranql.ejb.ReadOnlyCMPFieldAccessor.set(ReadOnlyCMPFieldAccessor.java:44)
>> at org.openejb.entity.cmp.CMPSetter.invokeInstance(CMPSetter.java:74)
>> at org.openejb.entity.cmp.CMPMethodInterceptor.intercept(CMPMethodInterceptor.java:75)
>>
>>
> Based on this stack-trace, I confirm that the CMP field orderId is
> mapped to a foreign key.
>
>>Here is the ejbCreate method that is failing
>>
>> public OrderLineEntPK ejbCreate(int id, Integer orderId, String itemId, int quantity, BigDecimal totalValue,
>> int olineStatus, java.sql.Date shipDate, BigDecimal msrp) throws CreateException {
>>
>> if( debugging )
>> debug.println(3, "ejbCreate of ol_id = " + id + ", o_id = "
>> + orderId);
>>
>> setId(id);
>> setOrderId(orderId); <==================== This is the line that is failing.
>> setItemId(itemId);
>> setQuantity(quantity);
>> setTotalValue(totalValue.setScale(2, BigDecimal.ROUND_UP));
>> setOlineStatus(olineStatus);
>>
>>
>>
>>OrderId is the FK to the Order.
>>
>>
> Fields mapped to foreign key columns are read-only. They are read-only
> for the following reason:
> Let's assume that:
> * we have one existing line item lineItemEntity;
> * lineItemEntity is already related to an order orderEntity;
> * orderEntity is related to two line items, lineItemEntity (as expected)
> and lineItemEntity2;
> * we want to relate lineItemEntity to a new order orderEntity2;
> * orderEntity2 is related to zero line items; and
> * line item defines a CMR field order to set its related order.
>
> In this specific scenario, if we set the CMR field order of
> lineItemEntity to orderEntity2, then:
> * orderEntity2 is now related to the line item lineItemEntity; and
> * orderEntity is now related to only one line item lineItemEntity2.
>
> In this same scenario, if we set the CMP field orderId of lineItemEntity
> to the primary key of orderEntity2, then I am not sure of what the
> result should be. Indeed, it is a CMP field and no specfic semantic is
> attached to it.
>
> To some extent, I am not sure that we should allow developers to update
> relationships via a direct update to the underlying foreign key columns.
> We could implement a fix to have a CMR semantic for CMP fields mapped to
> foreign ley columns; yet it does not sound good. Having said that, I do
> not have a strong opinion and I am happy to support such a scenario, if
> we need to.
>
> Also, it is worth to notice that such a potential fix will only be able
> to handle CMP having simple primary keys. CMP having compound primary
> keys will still have a read-only approach.
>
>>First question is the deployment right for this scenario? If it is, then I think that the container is not acting correctly. This code runs on WebLogic, Sun One, WebSphere, etc.
>>
>>
> Do you know if they properly support such scenarii (the CMP field must
> have a CMR semantic)? Also, do you know if they do not allow such
> scenarii in the case of compound PK CMP?
>
> Thanks,
> Gianny