Presentation number seven was about databases. Tomas Barina prepared an introduction of the database technology for web servers. He has reviewed the SQL basics and explained some of the specifics of the NoSQL database technology. Mainly he has focused on the Google App Engine data services: datastore, memcache and blobstore. New datastore with five 9s is the recommended choice. Then he continued with some APIs recommendations, there are two java choices JDO and JPA for GAE. Large part of the session was devoted to a sample code. Tomas has shown how to set the database, write the basic CRUD operations and how to test the code using a REST client and datastore/viewer. Samples of the memcache usage were also explained with some comments about efficiency. The whole presentation is giving complete advice on how to configure and use persistence in GAE.
See the presentations
The next session will put all three presentations together. The result will be a simple code for a web application running on a Galaxy tablet. The native client will display an entry field for name, surname and date of birth. The user will fill-in data and save them on GAE. The next “activity” screen will read the data from the cloud and display it. This final application will complete the web apps how-to. The whole code will be published on github.
We had two interesting contributions in discussion forum. Adam send a post showing how to use WiFi instead of the USB cable for the Galaxy tablet during the development. Very nice and useful, no wires cluttering the table. The second contribution describes an API for the university information system called KOS. Tonda put together sample code for authentication and data access. This is the starting point for all teams working on applications requiring the schedule and other data from KOS. Michal has published description of a small game on his blog.
I have reviewed the teams development sites to check the activity. I have found good and interesting progress. Happy meal team produced nice wireframes for their application.
Car share has developed lively video showing authentication, great job!
Conclusions: Some teams have made great progress. It looks like some do not like documenting. Some of the teams need to wake up and begin working. But overall, I thing, we are doing great job!