How to get all the kinds in the google app engine datastore?

Question

Hi, i'm using java to code for GAE, i've read through the GAE java low level api and can't find any answer to my question yet.

I wanna know if there's a way where i can call a method/ do a JDOPL and it returns all the different kinds of entities in my datastore.

Thanks!

Answer 1

You could use the datastore statistics API:

http://code.google.com/appengine/docs/java/datastore/stats.html

It looks like the __Stat_Kind__ statistic will give you the info you want.

Answer 2

i found a working solution in: (it doesn't work in local deployment server as of jul 9 2010)

http://groups.google.com/group/google-appengine-java/browse_thread/thread/d13d268242083db6/5bb868b394d09c13?show_docid=5bb868b394d09c13&fwc=1&pli=1

DatastoreService datastore = DatastoreServiceFactory.getDatastoreService(); PreparedQuery global = datastore.prepare(new Query("Stat_Kind"));

for( Entity globalStat : global.asIterable() ) { Long totalBytes = (Long) globalStat.getProperty("bytes"); Long totalEntities = (Long) globalStat.getProperty("count"); String kindName = (String) globalStat.getProperty("kind_name"); resp.getWriter().println("[" + kindName + "] has " + totalEntities + " entities and takes up " + totalBytes + "bytes
"); }