Question

I’ve just started using web2py with Google AppEngine for an app of mine. For some reason, I’m unable to save/retrieve data using the DAL. Here’s the code I’m using:

At the end of db.py:

from aeoid import middleware
from aeoid import users
import json


db.define_table('files', 
                    db.Field('name', 'text'),
                    db.Field('path', 'text'),
                    db.Field('version', 'text', default="live"),
                    db.Field('hash', 'text'),
                    db.Field('data', 'text'),
                    db.Field('meta', 'text', default=json.dumps({'date':str(request.now)})),
                    db.Field('contributors', 'text', default=json.dumps([users.get_current_user()])),
                    db.Field('lasttime', 'datetime', default=request.now)
                )

In my controller:

name = "TEST"
db.files[0] = dict(hash=name, name=name, path=name)
textobj = db.files[1]
if textobj is None:
  print "Fail: 500 Internal Server Error"

Here, textobj is always None for some reason.

What am I doing wrong?

EDIT: I’m using AppEngine SDK for Python on Windows.

Answer 1

When using the shortcut syntax db.table[id], id refers to the record ID. db.table[0] doesn’t actually refer to an existing record — it is just used to insert a new record.
Also, on GAE, the record IDs do not start at 1 and get incremented by 1, so your first inserted record will not have ID=1. You can either do:

textobj = db(db.files).select().first()

or

textobj_id = db.files.insert(hash=name, name=name, path=name)
textobj = db.files[textobj_id]

Finally, before deploying to GAE, make sure you have run the app locally using the GAE SDK appserver in order to properly generate the index.yaml file, as discussed here.