ODMG ordering problem with circular/bidirectional 1:1 references
----------------------------------------------------------------
Key: OJB-18
URL: http://issues.apache.org/jira/browse/OJB-18
Project: OJB
Type: Bug
Components: ODMG-API
Versions: 1.0.3
Environment: all
Reporter: armin waibel
Assigned to: armin waibel
odmg ordering problem when using circular/bidirectional 1:1 references, in this
case the ordering of objects doesn't change at commit.
Assume we have A-1:1->AA-1:1->AAA-1:1->A and the user persist the 'A' instance,
then the expected order is
[AAA, AA, A]
because start is A (specified by the user) and the last new object of the
circuit is AAA and for 1:1 references OJB first persist the reference. The
PB-api show this ordering, odmg show [A, AA, AAA] in this case.
The problem is the weight of the vertices in loops or circuits of 1:1
references, because all vertices have the same weight, so the odering doesn't
change.
*workaround*
Influence ordering by using TransactionExt.flush or make persist calls in the
correct order for all objects of the circuit
Example1, loop:
tx.begin();
Shop s1 = new Shop(name + "_1");
// when using flush() we can use the "natural" order
// without getting DB constraint violence.
database.makePersistent(s1);
// write to DB object without references
tx.flush();
ShopDetail sd = new ShopDetail(name + "_1");
// now set references
s1.setDetail(sd);
sd.setShop(s1);
// no need to persist the ShopDetail object
// (will be detected by OJB)
// but it doesn't matter if you do
// database.makePersistent(sd);
tx.commit();
Example2, loop:
tx.begin();
Shop s1 = new Shop(name + "_1");
ShopDetail sd = new ShopDetail(name + "_1");
s1.setDetail(sd);
sd.setShop(s1);
// madatory to persist referenced ShopDetail first, the Shop
// object will be detected automatic. In this case first the ShopDetail
// will be created and then the Shop
database.makePersistent(sd);
database.makePersistent(s1);
tx.commit();
--
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators:
http://issues.apache.org/jira/secure/Administrators.jspa
-
If you want more information on JIRA, or have a bug to report see:
http://www.atlassian.com/software/jira
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
