[appengine-java] Relationships between entities of of same kind
Some time ago, relationships between entities of same kind were not supported by the datastore. This was annoying in particular when trying to movel tree structures (@OneToMany relationship between MyClass and MyClass). The datastore documentation was pretty clear about this. I cannot find this limitation in the datastore documentation anymore. Have I missed a good news about a recent release allowing relationships inside entities of the same kind ? -- 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 google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
Re: [appengine-java] Relationships between entities of of same kind
2011/2/6 Cyrille Vincey crll...@gmail.com Some time ago, relationships between entities of same kind were not supported by the datastore. This was annoying in particular when trying to movel tree structures (@OneToMany relationship between MyClass and MyClass). The datastore documentation was pretty clear about this. I cannot find this limitation in the datastore documentation anymore. Have I missed a good news about a recent release allowing relationships inside entities of the same kind ? I tried it a few days ago (with JDO) and it didn't work. -- 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 google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
Re: [appengine-java] Re: Problem Authenticating against App Engine
The Nick's way is the good way. My note was about OAuth. Afaik Android AccountManager class uses ClientLogin for authentication on App Engine. Fabrizio On Sun, Feb 6, 2011 at 5:03 PM, Sky skysoftwaredes...@googlemail.comwrote: thanks for the answer. I will try it, as soon as my new mobile sim card has been activated ;). In the 2.3 emulator it worked with another account... ClientLogin: I did not find any sample code. The best documented way I found was Nick's blog. Maybe Google should provide some Tutorials/libs with sample code, that demonstrates the perfect way to authenticate an Android app with app engine using Google accounts... -- 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 google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
[appengine-java] Re: Relationships between entities of of same kind
Hi, I think that it is still in the doc: see last bullet point of http://code.google.com/appengine/docs/java/datastore/jdo/overview.html#Unsupported_Features_of_JDO regards didier On Feb 6, 4:48 pm, Jan Willies j...@willies.info wrote: 2011/2/6 Cyrille Vincey crll...@gmail.com Some time ago, relationships between entities of same kind were not supported by the datastore. This was annoying in particular when trying to movel tree structures (@OneToMany relationship between MyClass and MyClass). The datastore documentation was pretty clear about this. I cannot find this limitation in the datastore documentation anymore. Have I missed a good news about a recent release allowing relationships inside entities of the same kind ? I tried it a few days ago (with JDO) and it didn't work. -- 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 google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
[appengine-java] Re: Problem Authenticating against App Engine
thanks for the clarification! On 6 Feb., 17:16, Fabrizio Accatino fht...@gmail.com wrote: The Nick's way is the good way. My note was about OAuth. Afaik Android AccountManager class uses ClientLogin for authentication on App Engine. Fabrizio On Sun, Feb 6, 2011 at 5:03 PM, Sky skysoftwaredes...@googlemail.comwrote: thanks for the answer. I will try it, as soon as my new mobile sim card has been activated ;). In the 2.3 emulator it worked with another account... ClientLogin: I did not find any sample code. The best documented way I found was Nick's blog. Maybe Google should provide some Tutorials/libs with sample code, that demonstrates the perfect way to authenticate an Android app with app engine using Google accounts... -- 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 google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
[appengine-java] Re: Problem Authenticating against App Engine
One more question concerning the invalidation of the AuthToken. I read that it invalidates after 24h. What is when the Activity, holding the AuthToken (in NicksBlog the AppInfo class), ends (with finish() and onDestroy) and started again? In my opinion a new valid AuthToken is fetched every time the Appinfo class gets started. In this case, why do I have to invalidate the old AuthToken? On 6 Feb., 19:46, Sky skysoftwaredes...@googlemail.com wrote: thanks for the clarification! On 6 Feb., 17:16, Fabrizio Accatino fht...@gmail.com wrote: The Nick's way is the good way. My note was about OAuth. Afaik Android AccountManager class uses ClientLogin for authentication on App Engine. Fabrizio On Sun, Feb 6, 2011 at 5:03 PM, Sky skysoftwaredes...@googlemail.comwrote: thanks for the answer. I will try it, as soon as my new mobile sim card has been activated ;). In the 2.3 emulator it worked with another account... ClientLogin: I did not find any sample code. The best documented way I found was Nick's blog. Maybe Google should provide some Tutorials/libs with sample code, that demonstrates the perfect way to authenticate an Android app with app engine using Google accounts... -- 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 google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
[appengine-java] Re: How to produce a synchronized timestamp?
I'd love to hear what the official word on the reliability of clock synchronization is too. I think the docs say not to rely on it. One potential solution is to rely on one common time stamp clock source. For example a reliable 3rd party API that your code can query for a time stamp. You could set up a utility class to get the timestamp once and statically store the offset from the local JVM clock, so you only need to query the time stamp from the third part once per JVM start up. -- 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 google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
[appengine-java] Re: How to produce a synchronized timestamp?
Brett Slatkin: ...clocks aren't in sync. It doesn't work like that. Even with NTP it doesn't work like that. I saw a server the other day it was 40 minutes off. http://www.google.com/events/io/2010/sessions/high-throughput-data-pipelines-appengine.html -- 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 google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
Re: [appengine-java] Re: Problem Authenticating against App Engine
I follow another way: 1 - get auth token from AccountManager 2 - try to get the auth Cookie from AppEngine 3 - if step 2 fails, I invalidate the Auth token and restart from step 1. My very alpha code is here: http://fhtino.blogspot.com/2011/02/connet-android-app-to-google-app-engine.html Fabrizio On Sun, Feb 6, 2011 at 8:12 PM, Sky skysoftwaredes...@googlemail.comwrote: One more question concerning the invalidation of the AuthToken. I read that it invalidates after 24h. What is when the Activity, holding the AuthToken (in NicksBlog the AppInfo class), ends (with finish() and onDestroy) and started again? In my opinion a new valid AuthToken is fetched every time the Appinfo class gets started. In this case, why do I have to invalidate the old AuthToken? On 6 Feb., 19:46, Sky skysoftwaredes...@googlemail.com wrote: thanks for the clarification! On 6 Feb., 17:16, Fabrizio Accatino fht...@gmail.com wrote: The Nick's way is the good way. My note was about OAuth. Afaik Android AccountManager class uses ClientLogin for authentication on App Engine. Fabrizio On Sun, Feb 6, 2011 at 5:03 PM, Sky skysoftwaredes...@googlemail.com wrote: thanks for the answer. I will try it, as soon as my new mobile sim card has been activated ;). In the 2.3 emulator it worked with another account... ClientLogin: I did not find any sample code. The best documented way I found was Nick's blog. Maybe Google should provide some Tutorials/libs with sample code, that demonstrates the perfect way to authenticate an Android app with app engine using Google accounts... -- 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 google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en. -- 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 google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
[appengine-java] Re: How to produce a synchronized timestamp?
Interesting..I wasn't expecting such a skew. What about a remote google time service or something, I can't imagine nobody requires synced timestamps On Feb 6, 9:53 pm, Peter Ondruška peter.ondru...@gmail.com wrote: Well in that case I am a bit puzzled what shall I expect when storing two entities with datetime property with auto_now=true at the same time (from different instances). Shall I expect the datetime to differ that much? Not good.. -- 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 google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
[appengine-java] hard time modeling my database
Hi all,
It seems like i am doing this the wrong way and the datastore is giving me a
hard time making queries.
I've got a my own User class in my application and there is a Book class in
the application.
Now the Book class has an owner and a write attribute.
@Entity
class User {
@Id
private String email;
}
@Entity
class Book {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Key key;
private User owner;
private User writer;
}
I want to search the store for all owned books (on the users myPage)
Query query = getEntityManager().createQuery(SELECT b FROM Book b WHERE
b.owner == :owner);
query.setParameter(owner, owner);
ListBook books = query.getResultList();
Now the datastore is throwing ugly things to me like Key of parameter value
does not have a parent.
I'm realy lost here. Could anyone explain to me how i could solve this?
--
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[appengine-java] Incremental datastore backup for App Engine
Hi, Just thought i'd send this note as it might be of use to some of you. Here is a python script to execute on remote servers to backup your GAE app datastores. It'll work with Java apps if you install the RemoteApiServlet. http://androidisland.blogspot.com/2011/02/datastore-inremental-backup-script-for.html Regards, Eurig Jones -- 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 google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
Re: [appengine-java] Re: Relationships between entities of of same kind
Didier, Do you mean There is currently *a bug* preventing owned one-to-many relationships *where the parent and the child are the same class*, making it difficult to model tree structures. This will be fixed in a future release. You can work around this by storing explicit Key values for either the parent or children.. If so, that is a bug not a limitation. J On Sun, Feb 6, 2011 at 11:30 AM, Didier Durand durand.did...@gmail.comwrote: Hi, I think that it is still in the doc: see last bullet point of http://code.google.com/appengine/docs/java/datastore/jdo/overview.html#Unsupported_Features_of_JDO regards didier On Feb 6, 4:48 pm, Jan Willies j...@willies.info wrote: 2011/2/6 Cyrille Vincey crll...@gmail.com Some time ago, relationships between entities of same kind were not supported by the datastore. This was annoying in particular when trying to movel tree structures (@OneToMany relationship between MyClass and MyClass). The datastore documentation was pretty clear about this. I cannot find this limitation in the datastore documentation anymore. Have I missed a good news about a recent release allowing relationships inside entities of the same kind ? I tried it a few days ago (with JDO) and it didn't work. -- 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 google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en. -- 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 google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
[appengine-java] Re: hard time modeling my database
You want to store the Key of the User not the actual User. If you
store the User you are creating an owned relationship. This means
that the user can only be owned by one book. What you want is an
unowned relationship, which means storing the keys. Then your query
stays the same except you will need to add query.import(import Key)
--- not the exact syntax
On Feb 6, 5:04 pm, Arjan arjan.br...@gmail.com wrote:
Hi all,
It seems like i am doing this the wrong way and the datastore is giving me a
hard time making queries.
I've got a my own User class in my application and there is a Book class in
the application.
Now the Book class has an owner and a write attribute.
@Entity
class User {
@Id
private String email;
}
@Entity
class Book {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Key key;
private User owner;
private User writer;
}
I want to search the store for all owned books (on the users myPage)
Query query = getEntityManager().createQuery(SELECT b FROM Book b WHERE
b.owner == :owner);
query.setParameter(owner, owner);
ListBook books = query.getResultList();
Now the datastore is throwing ugly things to me like Key of parameter value
does not have a parent.
I'm realy lost here. Could anyone explain to me how i could solve this?
--
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Google App Engine for Java group.
To post to this group, send email to google-appengine-java@googlegroups.com.
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google-appengine-java+unsubscr...@googlegroups.com.
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