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
Cheers,
- Matt
