the default datastore for GAE is a NOSQL system of key-value pairs. it does not have the full concept of referenced tables, and does not support a join operation.
your options are to flatten your schema, putting all the necessary data in a single record rather than splitting it into many table, or to query the first table and then query the second table for the items referenced. I use a combination of both. if you are not in a hurry, sign up for the beta access to SQL on GAE (my invite was not yet approved so i have not used it yet). Massimo says it's great. :) cfh
