Max, thanks for letting me know. I'm going to work around it for now by turning it into a OneToMany and differentiating the values myself.
Len On Oct 29, 4:17 pm, "Max Ross (Google)" <maxr+appeng...@google.com> wrote: > This is a current limitation that I hope to get rid of fairly soon. The > problem is that the parent does not have the key of the child as a field. > Instead, in order to find the child, the parent issues an ancestor query to > find the single object of the appropriate type that is a direct descendant. > I describe the reason for this odd implementation in detail in my Google IO > talk <http://www.youtube.com/watch?v=2jW2iSKDipY> from last summer. An > annoying side effect of this implementation is that you can't have two > relationship fields of the same type because we have no way of knowing which > child is associated with which field. We'll get it straightened out in the > next few releases, I promise. > > Max > > > > On Wed, Oct 28, 2009 at 9:49 PM, lent <lentakeu...@gmail.com> wrote: > > > Hello, > > > I'm using JPA with SDK 1.2.5 and I'm having a problem with multiple > > owned One To One relationships where the relationships are to the same > > type. The code is as below and Contributor class has three owned One > > to One relationships to ContentValue. > > > What I'm finding is that when I set one of the One to One properties > > in one transaction (e.g. picutre) in one request and then later on in > > a different request and transaction I retrieve another of the One to > > One properties (e.g. tagData), I get back the ContentValue I set for > > the first property (picture). > > > I'm doing the following to set the property: > > > Contributor contributor = <load contributor here>; > > ContentValue picture = contributor.getPicture(); > > if ( picture == null ) { > > picture = new ContentValue(); > > contributor.setPicture( picture ); > > pictureContent.setContentValueType( ContentValueType.PICTURE ); > > } > > ... > > > If anyone knows why I'm having this problem, please let me know. > > > Regards, > > Len > > > Contributor.java > > ---------------- > > > package abc; > > > //import com.google.appengine.api.datastore.Key; > > //import com.google.appengine.api.datastore.KeyFactory; > > import org.datanucleus.jpa.annotations.Extension; > > > import javax.persistence.AttributeOverrides; > > import javax.persistence.CascadeType; > > import javax.persistence.Embedded; > > import javax.persistence.FetchType; > > import javax.persistence.Entity; > > import javax.persistence.Enumerated; > > import javax.persistence.GeneratedValue; > > import javax.persistence.GenerationType; > > import javax.persistence.Id; > > import javax.persistence.OneToMany; > > import javax.persistence.OneToOne; > > import javax.persistence.Transient; > > > import java.util.ArrayList; > > import java.util.Date; > > import java.util.List; > > import java.util.Date; > > > @Entity > > public class Contributor { > > �...@id > > �...@generatedvalue(strategy=GenerationType.IDENTITY) > > �...@extension(vendorName="datanucleus", key="gae.encoded-pk", > > value="true") > > private String id; > > > �...@enumerated > > private String firstName; > > > �...@enumerated > > private String lastName; > > > �...@onetoone(cascade = CascadeType.ALL, fetch = FetchType.LAZY ) > > private ContentValue picture; > > > �...@onetoone(cascade = CascadeType.ALL, fetch = FetchType.LAZY ) > > private ContentValue thumbnailPicture; > > > �...@onetoone(cascade = CascadeType.ALL, fetch = FetchType.LAZY ) > > private ContentValue tagData; > > > public void setId(String id) { > > this.id = id; > > } > > > public String getId() { > > return id; > > } > > > public void setFirstName(String firstName) { > > this.firstName = firstName; > > } > > > public String getFirstName() { > > return firstName; > > } > > > public void setLastName(String lastName) { > > this.lastName = lastName; > > } > > > public String getLastName() { > > return lastName; > > } > > > public void setPicture(ContentValue picture) { > > this.picture = picture; > > } > > > public ContentValue getPicture() { > > return picture; > > } > > > public void setThumbnailPicture(ContentValue thumbnailPicture) { > > this.thumbnailPicture = thumbnailPicture; > > } > > > public ContentValue getThumbnailPicture() { > > return thumbnailPicture; > > } > > > public void setTagData(ContentValue tagData) { > > this.tagData = tagData; > > } > > > public ContentValue getTagData() { > > return tagData; > > } > > > } > > > ContentValue.java > > ----------------- > > package abc; > > > import org.datanucleus.jpa.annotations.Extension; > > > import com.google.appengine.api.datastore.Blob; > > > import javax.persistence.AttributeOverrides; > > import javax.persistence.Entity; > > import javax.persistence.CascadeType; > > import javax.persistence.Enumerated; > > import javax.persistence.Embedded; > > import javax.persistence.GeneratedValue; > > import javax.persistence.GenerationType; > > import javax.persistence.Id; > > import javax.persistence.NamedQuery; > > import javax.persistence.OneToOne; > > > @Entity > > public class ContentValue { > > �...@id > > �...@generatedvalue(strategy=GenerationType.IDENTITY) > > �...@extension(vendorName="datanucleus", key="gae.encoded-pk", > > value="true") > > private String id; > > > �...@enumerated > > �...@extension(vendorName="datanucleus", key="gae.parent-pk", > > value="true") > > private String parentId; > > > �...@enumerated > > private ContentValueType contentValueType; > > > �...@enumerated > > private Blob content; > > > �...@enumerated > > private String contentType; > > > public void setId(String id) { > > this.id = id; > > } > > > public String getId() { > > return id; > > } > > > public void setParentId(String parentId) { > > this.parentId = parentId; > > } > > > public String getParentId() { > > return parentId; > > } > > > public void setContentValueType(ContentValueType contentValueType) { > > this.contentValueType = contentValueType; > > } > > > public ContentValueType getContentValueType() { > > return contentValueType; > > } > > > public void setContent(Blob content) { > > this.content = content; > > } > > > public Blob getContent() { > > return content; > > } > > > public void setContentType(String contentType) { > > this.contentType = contentType; > > } > > > public String getContentType() { > > return contentType; > > } > > } > > > ContentValueType.java > > --------------------- > > import java.io.Serializable; > > > package abc; > > > public enum ContentValueType implements Serializable { > > PICTURE, // content is a picture > > THUMBNAIL, // content is a thumbnail > > TAG_DATA // tag data > > }- Hide quoted text - > > - Show quoted text - --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. 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