You have a good point there. Thanks for the advice. I guess I would just
have run into that problem later. Maybe it would be a good idea to add
this advice to the user guide, where flattened relationships are
discussed. It took me, as a cayenne beginner, some time to figure out
how it is working. One emerging problem was solved in this conversation.
Maybe others will experience the same problems.
Michael Gentry schrieb:
Daniel,
I just re-ran your app after unchecking personID in your join table
(only bookID was set as the primary key). That causes SQL like this
to be produced:
INFO: DELETE FROM Person_is_author_of_book WHERE bookID = ?
May 12, 2008 2:45:31 PM org.apache.cayenne.access.QueryLogger logQueryParameters
INFO: [bind: 1->bookID:3]
That is incorrect for what you want. You need to make both a primary
key. If not, it will delete too many records (potentially) since it
is not qualifying the personID.
/dev/mrg
Hi
Thanks again. Setting at least one of the attributes as primary key solved
the problem. As far as I tested, it is not important which of the attributes
is assigned the primary key, but there has to be at least one PK. The PK
generation strategy is set to default by the modeller. Any changes to that
setting do not seem to affect the generated code, so everything seems to
work just as it should by now.
Michael Gentry schrieb:
[followup back to the user list]
Hi Daniel,
The first time I ran your test application it did indeed crash with
the missing WHERE clause (this is on Cayenne 3.x, too). I went into
your Cayenne Model, though, and on your Person_is_author_of_book table
(you didn't map it as a class, which is cool since you are flattening
it), I checked the PK/Mandatory checkboxes under the Attributes tab
for the DbEntity. Then I re-ran the application and it worked:
INFO: DELETE FROM Person_is_author_of_book WHERE bookID = ? AND personID =
?
May 12, 2008 12:17:06 PM org.apache.cayenne.access.QueryLogger
logQueryParameters
INFO: [bind: 1->bookID:2, 2->personID:2]
Try updating your model and see if it fixes your issue.
Thanks,
/dev/mrg
