在Google App Engine中配置数据库

Question

I've read and understand google APi for CRUD operation in data. But where is the data? Because normally to configure the persistance layer, we need to specify where the data is in the XML file. For ex: name of the database, login and password,... But how to do that with GWT? And how to physically create a real database in the google app engin? Thanks

Answer 1

I strongly recommend reading this help page from google: http://code.google.com/appengine/docs/java/gettingstarted/usingdatastore.html

But essentially you create your entity and persist and they'll create the tables for you. its pretty nifty give it a shot.

Answer 2

Google documentation is a reference for all of us. But is it a good start to grasp basic concepts? Not so much (especially when its examples use JDO or JPA)...

The following links should definitely help:

Fundamental Concepts of the Datastore (I do not endorse Objectify here - just this introductory page; but do give consideration to APIs such as Objectify and Twig-Persist after you get comfortable with basic concepts).

Life of a Datastore Write

Transaction Isolation in App Engine

and the rest of the Mastering the datastore series in your spare time ;-).

Introduction to low-level API

Some critique: Google App Engine's Datastore Falters Under Demand