Hi,
I'm having a problem with embedded objects.
My code looks something like this:
@PersistenceCapable
public class Parent {
@PrimaryKey
@Persistent(valueStrategy=IdGeneratorStrategy.IDENTITY)
@Extension(vendorName="datanucleus", key="gae.encoded-pk", value="true")
private String key;
@Persistent
@Embedded
private Child child;
public Child getChild() {
return child;
}
public void setChild(Child child) {
this.child = child;
}
}
@PersistenceCapable
@EmbeddedOnly
public class Child {
@Persistent
private String field;
public Child(String field) {
this.field = field;
}
}
With the code as above, I create an entity and persist it:
Parent parent = new Parent();
parent.setChild(new Child("foo"));
persistenceManager.makePersistent(parent);
Looking at the data store, I see there's a property in Parent
called "field", and it has the value "foo" as expected.
However, when I read the Parent object back from the data
store, parent.getChild() returns null. If I remove the
@Embedded and @EmbeddedOnly annotations and add a key
to Child, parent.getChild() returns the child properly.
Looking at the DataNucleus documentation [1],
I see there are "nullIndicatorColumn" and "nullIndicatorValue"
attributes to @Embedded, but setting e.g.
nullIndicatorColumn to "child" doesn't seem to have any effect
Am I doing something wrong?
[1]
http://www.datanucleus.org/products/accessplatform/jdo/annotations.html#Embedded
-ian
--
Ian Murdock
http://ianmurdock.com/
"Don't look back--something might be gaining on you." --Satchel Paige
--
You received this message because you are subscribed to the Google Groups
"Google App Engine for Java" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/google-appengine-java?hl=en.
