How to properly detect object not found in query?

Question

Generally, we'd prefer to catch the unchecked exceptions which JDO throws in
response to database operations that go awry. That said, there's one in
particular that's bothering us:
The most important and common one of these which we'd like to know about is
when a query or getObjectByID() fails because the desired object isn't in
the DB.
Currently, an exception is thrown, which we would presumably have to catch
and parse the message text of to determine if this was a row not found, vs.
a database problem?
Please tell me there's a better way to determine if a row(s) isn't(aren't)
found!
thanks,
david

Answer 1

Patrick -- I believe we just see them in getObjectById(), which is what we
do most often.
The subclass of JDODataStoreException that you'll throw is great.
I'd suggest that a property setting could configure kodo to return null to
getObjectById() instead -- ONLY for the case of object not found, for those
of us who might consider this a less-than-truly-exceptional case :)
thanks much,
david
"Patrick Linskey" <[email protected]> wrote in message
news:[email protected]..
David,
Also, a query should return a collection of size zero, and not throw an
exception.
Are you seeing exceptions only when executing getObjectById(), or also
when querying?
-Patrick
On Tue, 29 Apr 2003 05:03:23 -0400, david michaels wrote:
Generally, we'd prefer to catch the unchecked exceptions which JDO
throws in response to database operations that go awry. That said,
there's one in particular that's bothering us:
The most important and common one of these which we'd like to know about
is when a query or getObjectByID() fails because the desired object
isn't in the DB.
Currently, an exception is thrown, which we would presumably have to
catch and parse the message text of to determine if this was a row not
found, vs. a database problem?
Please tell me there's a better way to determine if a row(s)
isn't(aren't) found!
thanks,
david--
Patrick Linskey
SolarMetric Inc.