Well it partly worked, but enough to get by for development purposes
for awhile, so that's pretty good. I removed datanucleus-
appengine-1.0.3.jar from the Eclipse plugin and replaced it with
appengine-1.0.4.RC1.jar. First, I tried my data model unchanged and it
did not work. I got the same error message:
Caused by: java.lang.IllegalArgumentException: can't operate on
multiple entity groups in a single transaction. found both Element {
type: "Customer"
id: 1
}
and Element {
type: "Address"
id: 2
}
So, then I moved the reference to Address from the base class,
"Person" to the subclass, "Customer", and I was able to persist a
Customer. I'm assuming that any owned relationships will only work if
they emanate from the concrete class that you are trying to persist;
not a superclass. But I haven't tried this with, for example, a 3
level inheritance hierarchy, so I can't vouch for that. If I have to
use this type of inheritance in my app, I will post another message to
let people know how it turned out.
In the mean time, I'm hoping that we'll see an update to fix this
owned relationship by a superclass problem soon.
Rick
On Nov 20, 7:36 am, Rick Horowitz <[email protected]> wrote:
> I just examined the jars in some detail and see that there is only 1
> jar changed: datanucleus-appengine-1.0.3.jar -> datanucleus-
> appengine-1.0.4.RC1.jar. I'll upgrade that into the Eclipse plugin and
> do some tests. Unfortunately, my data model uses owned relationships
> from the base class, which I guess doesn't work just yet. I'll report
> back. Thanks.
>
> On Nov 19, 8:22 pm, Rick Horowitz <[email protected]> wrote:
>
> > Thank you for responding. This is not good, but I guess it could be worse.
> > Google could be ignoring these problems instead of fixing them. One more
> > question. What's the right way to install appengine-orm-1.0.4.rc1.zip with
> > the Eclipse App Engine SDK 1.2.6? Do I just replace all the jars in the SDK
> > with the jars from appengine-orm-1.0.4.rc1.zip?
>
> > Thanks very much.
>
> > Rick
>
> > On Thu, Nov 19, 2009 at 5:03 PM, Ikai L (Google) <[email protected]> wrote:
>
> > > The current version won't support inheritance, which may explain why this
> > > isn't working. It looks like fixes for inheritance will be going out when
> > > datanucleus is updated:
>
> > >http://code.google.com/p/datanucleus-appengine/issues/detail?id=25
>
> > > The stack trace looks different, though, but that may be because you are
> > > using a transaction, and the transaction manager is taking a look at the
> > > key
> > > that is being generated and does not recognize "Address" as having
> > > "Customer" as an ancestor.
>
> > > I'm not sure why you need a transaction here, though. It doesn't look like
> > > Customer or Address will be out of sync. You could also accomplish the
> > > same
> > > thing using an embedded class, though I suppose that wouldn't work if
> > > multiple customers had the same address and addresses changed frequently
> > > (though you could solve this by updating all matching embedded addresses
> > > if
> > > an address changes in a transaction, making the Address the parent of the
> > > Customer).
>
> > > ---------- Forwarded message ----------
> > > From: Rick Horowitz <[email protected]>
> > > Date: Thu, Nov 19, 2009 at 1:44 PM
> > > Subject: [google-appengine] Re: Can't get owned relationship working with
> > > JDO and subclass
> > > To: Google App Engine <[email protected]>
>
> > > Does anyone have any idea why this won't work? I've tried every option
> > > I can think of and it still doesn't work. Would really appreciate some
> > > help from someone knowledgeable about JDO and gae. I'm assuming it's
> > > pretty basic to persist a subclass object whose superclass (base
> > > class) references an owned object, but gae doesn't seem to like it. I
> > > tried the base class as abstract and concrete, and tried the keys as
> > > type Key and as encoded String. No luck.
>
> > > Thanks very much for any help.
>
> > > Rick
>
> > > On Nov 15, 11:40 pm, Rick Horowitz <[email protected]> wrote:
> > > > I'm trying to persist a simple class relationship using JDO. My code
> > > > is listed below and here's a brief overview of what I'm trying to do:
>
> > > > I have 3 classes:
>
> > > > Person, Customer (extends Person), and Address (referenced from
> > > > Person). If I create a Person instance and an Address instance and
> > > > call setAddress() on Person, then call
> > > > PersistenceManager.makePersistent(), the objects get saved correctly.
>
> > > > However, if I create a Customer instance and an Address instance, I
> > > > get the following error message:
>
> > > > java.lang.IllegalArgumentException: can't operate on multiple entity
> > > > groups in a single transaction. found both Element {
> > > > type: "Customer"
> > > > id: 1}
>
> > > > and Element {
> > > > type: "Address"
> > > > id: 2
>
> > > > }
>
> > > > I am doing this from within a JDO transaction.
>
> > > > Here's the code:
>
> > > > First, the server-side code that attempts to create and persist the
> > > > objects:
>
> > > -----------------------------------------------------------------------------------------------------------
>
> > > > PersistenceManager pm =
> > > PMF.get().getPersistenceManager();
> > > > Transaction txn = pm.currentTransaction();
> > > > try {
> > > > txn.begin();
> > > > Address a = new Address("15 Post Road", "",
> > > "Anytown", "New York",
> > > > "USA", "03801");
> > > > Customer c = new Customer();
> > > > c.setAddress(a);
> > > > c.setFirstName("John");
> > > > c.setLastName("Doe");
> > > > pm.makePersistent(c);
> > > > txn.commit();
> > > > } finally {
> > > > if (txn.isActive()) {
> > > > txn.rollback();
> > > > }
> > > > pm.close();
> > > > }
>
> > > > Person:
> > > > -----------
>
> > > > @PersistenceCapable(identityType = IdentityType.APPLICATION)
> > > > @Inheritance(strategy = InheritanceStrategy.SUBCLASS_TABLE)
> > > > public abstract class Person implements Serializable {
>
> > > > public static enum PERSON_KEYS {
> > > > firstName,
> > > > lastName,
> > > > workEmail,
> > > > phoneNbr
> > > > }
> > > > static final long serialVersionUID = 100L;
>
> > > > @PrimaryKey
> > > > @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
> > > > @Extension(vendorName = "datanucleus", key = "gae.encoded-pk",
> > > > value="true")
> > > > private String key;
> > > > private String firstName;
> > > > private String lastName;
> > > > private String middleInitial;
> > > > private String workEmail;
> > > > private String homeEmail;
> > > > private String phoneNbr;
> > > > @Persistent
> > > > private Address address = new Address();
> > > > private String salutation;
>
> > > > public Person() {
> > > > }
>
> > > > public String getKey() {
> > > > return key;
> > > > }
>
> > > > public void setKey(String key) {
> > > > this.key = key;
> > > > }
>
> > > > public String getWorkEmail() {
> > > > return (this.workEmail);
> > > > }
>
> > > > public void setWorkEmail(String workEmail) {
> > > > this.workEmail = workEmail;
> > > > }
>
> > > > public String getHomeEmail() {
> > > > return homeEmail;
> > > > }
>
> > > > public void setHomeEmail(String homeEmail) {
> > > > this.homeEmail = homeEmail;
> > > > }
>
> > > > @NotPersistent
> > > > public String getEmailAddress() {
> > > > String emailAddr = getWorkEmail();
> > > > if ((emailAddr == null) || (emailAddr.length() ==0))
> > > > emailAddr = getHomeEmail();
> > > > return emailAddr;
> > > > }
>
> > > > public void setEmailAddress(String emailAddress) {
> > > > setWorkEmail(emailAddress);
> > > > }
>
> > > > @NotPersistent
> > > > public String getFullName() {
> > > > StringBuffer sb = new StringBuffer();
> > > > if (getFirstName() != null) {
> > > > sb.append(getFirstName());
> > > > sb.append(" ");
> > > > }
> > > > if ((getMiddleInitial() != null) &&
> > > (getMiddleInitial().length() >
> > > > 0)) {
> > > > sb.append(getMiddleInitial());
> > > > sb.append(" ");
> > > > }
> > > > if (getLastName() != null) {
> > > > sb.append(getLastName());
> > > > }
> > > > return sb.toString();
> > > > }
>
> > > > public String getFirstName() {
> > > > return (this.firstName);
> > > > }
>
> > > > public void setFirstName(String firstName) {
> > > > this.firstName = firstName;
> > > > }
>
> > > > public String getLastName() {
> > > > return (this.lastName);
> > > > }
>
> > > > public void setLastName(String lastName) {
> > > > this.lastName = lastName;
> > > > }
>
> > > > public Address getAddress() {
>
> > > > public void setAddress(Address address) {
> > > > this.address = address;
> > > > }
>
> > > > public String getMiddleInitial() {
> > > > return middleInitial;
> > > > }
>
> > > > public void setMiddleInitial(String middleInitial) {
> > > > this.middleInitial = middleInitial;
> > > > }
>
> > > > public String getPhoneNbr() {
> > > > return phoneNbr;
> > > > }
>
> > > > public void setPhoneNbr(String phoneNbr) {
> > > > this.phoneNbr = phoneNbr;
> > > > }
>
> > > > }
>
> > > > Customer:
> > > > ---------------
>
> > > > @PersistenceCapable(identityType = IdentityType.APPLICATION)
> > > > public class Customer extends Person implements Serializable {
>
> > > >
>
> ...
>
> read more »
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