Objects are updated/created in the database in wrong order

Question

Hello,
I have three objects tied with certain relations: Ticket, Type and
Solution.
Relation between Ticket and Solution is unidirectional one-to-one - ticket
may contain one solution. Relation between Type and Solution is one-to-many
bi-directional.
During transaction I do the following:
1) instantiate new Solution and add it to the Type;
2) set this Solution to the Ticket.
On commit Kodo tries to update ticket before creating solution in the
database. What am I doing wrong?
Thank you in advance.
Best regards,
Alexey Maslov

Answer 1

Alex,
Thank you. It worked :)
"Alex Roytman" <[email protected]> wrote in message
news:[email protected]...
The best way to handle update/insert order is not to rely on it. Not only
foreign key sensitive to order but unique constraints too. So if your
database supports it (and most decent databases do) use defferred
constraints - the ones which get applied on commit not on
insert/update/delete and you will be fine
"Alexey Maslov" <[email protected]> wrote in message
news:[email protected]...
Patric,
Thank you for response.
It's not about Type->Solution relation. We've got constraint from
Ticket
to Solution. But we need to load Ticket to get it's Type.
It's a problem to instantiate the Solution before loading Type. Thething
is that Type object is used to construct Solution automatically adding
it
to
internal collection.
This is done to overcome JDO deficiency in relation maintenance. I'vefound
this pattern in Robin Roos' book.
create...() method usage makes sure that dependent object is added tothe
parent after each creation. Adding objects manually after creation wouldbe
error-prone and code-cluttering.
Where's that "transparency" so much told about on JDOCentral?
P.S. I wonder how this pattern works in other places?
"Patrick Linskey" <[email protected]> wrote in message
news:[email protected]...
Alexey,
In Kodo JDO 2.3 and 2.4, object changes are flushed to the database in
the order that the objects are first enlisted in the transaction. So,
if
you instantiate the Solution object before loading Type, everything
should work the way you want it to.
We have more sophisticated foreign key constraint satisfaction code in
internal codebases -- expect to see this hit production in the nextfew
months.
-Patrick
Alexey Maslov wrote:
Hello,
I have three objects tied with certain relations: Ticket, Type and
Solution.
Relation between Ticket and Solution is unidirectional
one-to-one -
ticket
may contain one solution. Relation between Type and Solution is
one-to-many
bi-directional.
During transaction I do the following:
1) instantiate new Solution and add it to the Type;
2) set this Solution to the Ticket.
On commit Kodo tries to update ticket before creating solution inthe
database. What am I doing wrong?
Thank you in advance.
Best regards,
Alexey Maslov
Patrick Linskey [email protected]
SolarMetric Inc. http://www.solarmetric.com