NDB delete & amp; consistency

I understand that NDB queries (reading) are eventually consistent. But what about deleting and writing? For example will running the below code always (eventually) result in one defective widget being in our datastore: # get rid of defective widgets

Update multiple fields on the Google NDB entity

Working with Google App Engine for Python, I am trying to create and then update an ndb entity. To update a single property, you can just access the property using a dot, e.g. post.body = body But I would like to know if there is a simple way to upda

Storing and recovering data from Datastore using JDO

Can you please help me to solve this problem. Here I'm storing some data to Datastore with JDO Interface using AJAX call. I'm storing the data to datastore and Retrieving it immediately. While Retrieving some times it returns NULL as a response(Its n

When to use POJO to define entities in google appengine?

I am new to Google Appengine. While learning the basics of Google Datastore, I came across the concepts on Entities and saw 2 ways of defining and storing them. One is to use POJOs with annotations to define entities and register them in Objectify be

Organizing User Profile Images on Google App Engine

I am very new to storing pictures on a web server. Currently I am using Google App Engine's Cloud SQL for my database to house all of my user's information (username, password, etc). I was reading about how most people DON'T store pictures in a datab

Create does not work in GAE Datastore Viewer

When I try to create some entities I don't see the option to input fields. I just see the SaveEntity button. However I can view all the existing entities. What is very strange is - there is another entity called VideoEntity for which the create did n

How to debug GAE python, gql and datastore?

I have been struggling to find ways to debug some python scripts and gql datastore queries in GAE using textmate. For the gql queries, can we print the queries to see what's in the database? (like php print_r function). For the .py files, anyway we c

Recipe needed to upload data to the Google App Engine datastore

While I've been busy finishing my Google App Engine solution during the last several months, I now find Google has me painted me into a corner due to changes and differences between the local dev_server and appspot. The scenario: My app is deployed o

A more effective way to prevent duplicate voting

There are a few questions similar to this already but I am hoping for a somewhat different answer. I have a website on Google App Engine in Python and I let registered users vote on posts, either up or down, and I only want each user to be able to vo

How to get the entity with the most recent date

Does anyone have any idea how to retrieve the last(with the newest date) entity in objectify? I know how to make a query but how to retrieve the one with the newest date? List<Transaction> fetched2 = ofy.query(Transaction.class).filter("somepro

App Engine Multiple Name Locations

Recently there's been some data structure changes in our app, and we decided to use namespaces to separate different versions of of the data, and a mapreduce task that converts old entities to the new format. Now that's all fine, but we don't want to

Join the data store

How to implement joins in datastore ,iam using java ,i want to insert a file(Excel,img,word or pdf) into datastore and retrive a file from datastore.Joins are not supported in GAE. See this documentation: http://code.google.com/appengine/docs/java/da

Unique unique identifier among the entity groups in App Engine

I've searched around for answers to this question, but not found anything quite on the money. I'd be really interested to hear people's thoughts. Here goes: In Google AppEngine, lets say I have a number of User objects, each of which can have a numbe

File download on GAE using gwt-upload

Can someone know how to upload files using gwt-upload implementation at http://code.google.com/p/gwtupload/ on Google Application Engine.The download page lists the gwtupload-gae artifacts, which are "GwtUpload for GAE servers".

GAE / J Databank: How to Create an IN Query with JDO

I am trying to query a collection of entities by its key in the Google App Engine datastore. This is the query I am trying to execute with no success: Query query = pm.newQuery(Fix.class); query.setFilter("__key__ IN param"); query.declareParame

GAE: getting the key of the entity you just created

I'm creating a new entity like: some_model = ModelName( attr1 = ..., attr2 = ..., attr3 = ..., attr4 = ... ).put() Is there anyway to get the key of this newly created entity? I tried doing some_model.key() put that does not work.The return value of

GAE image publication in Datastore via the Django form

I'm working on a little side project that involves posting an avatar to a users profile page, seems straight forward enough. I'm following the instructions from the "Using the Images Python API" on the GAE web site. The sample they provide doesn

App Engine Datastore IN Operator - how to use?

Reading: http://code.google.com/appengine/docs/python/datastore/gqlreference.html I want to use: := IN but am unsure how to make it work. Let's assume the following class User(db.Model): name = db.StringProperty() class UniqueListOfSavedItems(db.Mode