Google App Engine：为具有 SQL 背景的人员介绍他们的数据存储 API？
除了 Google 提供的 Google App Engine 文档之外，是否有人还有任何好的信息，该文档为具有 MS SQL 背景的人员提供了很好的概述，以移植他们的知识并有效地使用 Google App Engine 数据存储 API。
例如，如果您有一个自行创建的用户表和消息表
，其中用户和消息之间存在关系（通过 UserID 连接），那么该结构在 Google App Engine 中将如何表示？
SELECT * FROM Users INNER JOIN Message ON Users.ID = Message.UserID
Does anyone have any good information aside from the Google App Engine docs provided by Google that gives a good overview for people with MS SQL background to porting their knowledge and using Google App Engine Data Store API effectively.
For Example, if you have a self created Users Table and a Message Table
Where there is a relationship between Users and Message (connected by the UserID), how would this structure be represented in Google App Engine?
SELECT * FROM Users INNER JOIN Message ON Users.ID = Message.UserID
如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。
绑定邮箱获取回复消息
由于您还没有绑定你的真实邮箱，如果其他用户或者作者回复了您的评论，将不能在第一时间通知您！
发布评论
评论（6）
我认为这是基础知识：键和实体组
在 appengine 文档中查找它。 （我是新来的，所以无法发布链接）
I think this is the basics : Keys and Entity Groups
look for it in appengine docs. (I'm new here so can't post a link)
我曾研究过它，但不是专家，尽管谷歌应用程序引擎是非常好的东西，它是未来，因为它实现了平台即服务和软件即服务。 Google应用程序引擎提供非关系数据库。 所以你真的不能在这里写关系。
问候，
高拉夫·J
I have worked on it but not a expert though Google app engine is very good thing and it is the future as it implements Platform as a Service and Software as a Service. Google app engine provides a non- relational database. So you cantreally write relationships here.
Regards,
Gaurav J
这些链接很棒，但主要偏向于 python，我使用的是 GWT，因此必须使用 GAE 的 java 风格，有没有人有任何示例说明如何在 java 版本的 GAE 中实现这些“连接”等效项？
干杯，
约翰
These links are great, but are predominantly python biased, I am using GWT, and therefore have to use the java flavour of GAE, does anyone have any examples of how to achieve these "join" equivalencies in the java version of GAE?
Cheers,
John
独立的 GAE SDK 很难用于将数据放入 Google App Engine 数据存储中以及从 Google App Engine 数据存储中检索数据。
“Objectify”是一个 GAE 扩展，它使这些操作变得更加容易。 可以在此处找到 Objectify wiki 和源代码。 我强烈建议在您的 GAE 项目中使用 Objectify。
http://code.google.com/p/objectify-appengine/
以下是有关将 Objectify 与应用程序引擎结合使用的一些教程。 按照这些教程，您将立即存储和检索数据。
http://www.fishbonecloud.com /2010/11/use-objectify-to-store-data-in-google.html
The standalone GAE SDK is pretty difficult to use for putting data into and retrieving data from the Google App Engine data store.
"Objectify" is a GAE extension that makes these operations much easier. The Objectify wiki and source code can be found here. I strongly recommend using Objectify in your GAE project.
http://code.google.com/p/objectify-appengine/
Here are a couple of tutorials on using Objectify with the app engine. Follow these tutorials and you will be storing and retrieving data in no time.
http://www.fishbonecloud.com/2010/11/use-objectify-to-store-data-in-google.html
这是一个很好的链接：使用 Google App Engine 进行一对多加入。
http://blog.arbingersys。 com/2008/04/google-app-engine-one-to-many-join.html
这是另一个很好的链接：使用 Google App Engine 进行多对多加入：
http://blog.arbingersys.com/2008/04/google-app- engine-many-to-many-join.html
以下是关于上述两个链接的精彩讨论：
http://groups.google.com/group/google-appengine/browse_thread/thread/e9464ceb131c726f/6aeae1e390038592?pli=1
我个人认为讨论中的此评论提供了有关 Google App Engine 数据存储的丰富信息：
http:// /groups.google.com/group/google-appengine/msg/ee3bd373bd31e2c7
进行了更多搜索，发现了这篇 Google 文档文章：
http ://code.google.com/appengine/articles/modeling.html
Here is a good link: One to Many Join using Google App Engine.
http://blog.arbingersys.com/2008/04/google-app-engine-one-to-many-join.html
Here is another good link: Many to Many Join using Google App Engine:
http://blog.arbingersys.com/2008/04/google-app-engine-many-to-many-join.html
Here is a good discussion regarding the above two links:
http://groups.google.com/group/google-appengine/browse_thread/thread/e9464ceb131c726f/6aeae1e390038592?pli=1
Personally I find this comment in the discussion very informative about the Google App Engine Data Store:
http://groups.google.com/group/google-appengine/msg/ee3bd373bd31e2c7
Searched around a bit more and came across this Google Doc Article:
http://code.google.com/appengine/articles/modeling.html
我可以通过视频链接来补充上面的优秀答案吗：
http://sites.google.com/site/io/building-scalable-web-applications-with-google-app-engine
这是 Google 的 Brett Slatkin 的精彩演讲用一个小时的时间来了解您需要考虑应用程序的特殊方式，然后才能期望它能够很好地扩展。 如果您来自关系背景，那么有些真正的 WTF（例如数据库查询中没有 count()）会让您陷入困境。
Can I supplement the excellent answer further above with a link to a video:
http://sites.google.com/site/io/building-scalable-web-applications-with-google-app-engine
It's a great talk by Google's Brett Slatkin who talks for an hour about the special way you need to think about your application before you can expect it to scale well. There are some genuine WTFs (such as no count() in db queries) that will cause you to struggle if you are coming from a relational background.