Hi Lon,
That's a really tricky question. Cayenne seems to stand firm on not
updating something that didn't change.
The shortest path as I see it is to trick Cayenne into believing such
fields are changed.
Here's a small prototype that does the trick.
It uses reflection to get some private parts of the context,
probably you could customize the Cayenne stack a bit
in order to make this more user-friendly.
public class ForceUpdateUtil {
private final Method methodGetChanges;
private final Field fieldSnapshot;
public ForceUpdateUtil() {
try {
methodGetChanges =
ObjectStore.class.getDeclaredMethod("getChangesByObjectId");
fieldSnapshot = ObjectDiff.class.getDeclaredField("snapshot");
} catch (NoSuchMethodException | NoSuchFieldException ex) {
throw new RuntimeException(ex);
}
methodGetChanges.setAccessible(true);
fieldSnapshot.setAccessible(true);
}
public void forceUpdate(Persistent persistent, String attribute) {
DataContext objectContext = (DataContext)persistent.getObjectContext();
try {
@SuppressWarnings("unchecked")
Map<Object, ObjectDiff> changesById = (Map<Object,
ObjectDiff>) methodGetChanges.invoke(objectContext.getObjectStore());
ObjectDiff objectDiff = changesById.get(persistent.getObjectId());
@SuppressWarnings("unchecked")
Map<String, Object> snapshot = (Map<String, Object>)
fieldSnapshot.get(objectDiff);
// here's an actual action we want
// we tell the cached snapshot that the field have null value
instead of the real one
// so that flush action will think there's a change and it
needed to be committed
snapshot.put(attribute, null);
} catch (InvocationTargetException | IllegalAccessException ex) {
throw new RuntimeException(ex);
}
}
}
And here is the usage example.
Note that you need to have some changes for the object:
@Test
public void test() {
ForceUpdateUtil util = new ForceUpdateUtil();
Artist artist = SelectById.query(Artist.class, 1).selectOne(context);
assertNotNull(artist);
artist.setDateOfBirth(new Date());
util.forceUpdate(artist, Artist.ARTIST_NAME.getName());
context.commitChanges();
}
On Wed, May 3, 2023 at 12:58 AM Lon Varscsak <lon.varsc...@gmail.com> wrote:
>
> Haha, yeah, it's a bit of an odd situation...could you point me to the
> right bit in your source where I could tinker?
>
> On Fri, Apr 28, 2023 at 4:59 AM Andrus Adamchik <aadamc...@gmail.com> wrote:
>
> > Hi Lon,
> >
> > certainly not via "standard" means. That logic is not configurable. But
> > everything is customizable of course :)
> >
> > Thanks,
> > Andrus
> >
> > > On Apr 27, 2023, at 12:09 AM, Lon Varscsak <lon.varsc...@gmail.com>
> > wrote:
> > >
> > > Hey all,
> > >
> > > I of course have an unusual situation that I'm not sure how to handle.
> > :)
> > >
> > > I was going to write a lot of background, but I don't know if it would
> > help
> > > or just confuse the situation. 🤣
> > >
> > > The situation I have is in one specific situation, I'd like Cayenne to
> > > always add an attribute to the UPDATE/INSERT statements, not just if the
> > > value is changed. Can you think of any way to achieve that?
> > >
> > > Thanks,
> > >
> > > Lon
> >
> >
--
Best regards,
Nikita Timofeev
