Craig,
I favor the exception for this case. The way we've defined setUnique,
it acts somewhat like an assertion, and the semantic should remain the
same for both execute and delete.
Regards,
Wes
Craig L Russell wrote:
Hi Michael,
Sounds good.
I was thinking some more about this issue and would like some feedback.
I think that we should make the query.execute and
query.deletePersistentAll methods as similar as possible, meaning that
they both should throw an exception if the cardinality of the results
is not zero or one.
I'll have a proposed wording for the specification later, but for now
let's go with the patch.
Thanks,
Craig
On Nov 28, 2005, at 5:35 AM, Michael Watzek wrote:
Hi Craig,
I have added a second patch to JDO-166. It adds a unique query to the
array of INVALID_QUERIES which is supposed to throw a
JDOUserException at deletePersistentAll because the number of
affected rows in the database exceeds 1.
Regards,
Michael
Hi Michael,
I'd expect a JDOUserException to be thrown.
The spec says
<spec 14.6.11>
void setUnique(boolean unique);
A14.6.11-1 [When the value of the Unique flag is true, then the
result of a query is a single value, with null used to indicate
that none of the instances in the candidates satisfied the filter.
If more than one instance satisfies the filter, and the range is
not limited to one result, then execute throws a JDOUserException.]
</spec 14.6.11>
I can add a similar description to the deletePersistentAll methods.
It might require the JDOUserException to be thrown before actually
deleting anything (the semantics of the method are such that a
select needs to be executed against the datastore anyway before the
delete occurs).
Another alternative is to disallow the Unique flag for
deletePersistentAll. But that's not what I would choose.
Craig
On Nov 25, 2005, at 6:07 AM, Michael Watzek wrote:
Hi,
I have a question concerning unique deletion by query:
Assuming a unique JDO query would throw a JDOUserException in
execute() because the result is not unique, would you expect a
JDOUserException thrown in deletePersistentAll()?
The spec does not require this and I'm not sure if we should add a
negative test case checking this.
Regards,
Michael
