I may be missing something (I have just started to read this) but I have a fundamental question: It seems to me entity groups (no matter how "limited" you consider them) are also useful and critical for things like updating, say, a user registration to a conference which may very well involve more than one table item:
person.id and registration.id and payment.id and coupon.id (for example). It seems to me "entity group" is a useful concept that should scale accross to SQL dbs in some way also. By not abstracting this appropriately, it seems we are creating (practically looking at this) more limitations than GAE has in reality. Am I missing something? Thanks, Yarko On Fri, Feb 20, 2009 at 11:33 AM, Robin B <[email protected]> wrote: > > The only easy way to set parent= is to bypass the DAL, because you do > not get easy access to the google key for the entity that is needed to > set a parent=. > > To use Google specific stuff, you can use the gae_db.Model directly. > > To effectively use Google logins, you *must* use gae_db.UserProperty > (users can change the email associated with their google account, so > it is the only way to reliably/uniquely identify a user). > > For example, I use this for Google users on http://ru.ly: > > class GaeUsers(gae_db.Model): > user = gae_db.UserProperty() > created_at = gae_db.DateTimeProperty(auto_now_add=True) > > def get_current_user(): > user = gae_users.get_current_user() > local_user = None > if user: > local_user = GaeUsers.all().filter('user =',user).get() > if local_user is None: > local_user = GaeUsers(user=user) > local_user.put() > return local_user > > > Robin > > > On Feb 20, 11:13 am, "Sebastian E. Ovide" <[email protected]> > wrote: > > On Fri, Feb 20, 2009 at 12:36 AM, Robin B <[email protected]> wrote: > > > > > I have the transactions working, but it is not fully compatible with > > > web2py DAL, but it could be soon ( needs type coercion, db.table.ALL, > > > etc) Also in web2py, you cannot set the entity group when inserting, > > > so transactions will only involve 1 record. (eg atomically read/ > > > modify/write a counter in a transaction) > > > > that is great, at least we can do counters !... > > > > and how could we specify a parent in a antity with web2py ? is there any > > simple way ? > > > > thanks ! > > > > > > > > > If you needed transactions immediately, you could do this: > > > > > from google.appengine.ext import gdb > > > > > def txn(): > > > post = db.posts[post_id] > > > post.update_record(title='foo') > > > return post > > > > > post = gdb.run_in_transaction(txn) > > > > > On a side note, I have batch operations working too. But I recently > > > read that batch operations are just O(n), which unfortunately means no > > > joins or efficient batch operations will be possible for now, but I > > > have not benchmarked it on the real google datastore to know for sure. > > > > > Robin > > > > > On Feb 19, 3:31 pm, sebastian <[email protected]> wrote: > > > > Hi All, > > > > > > is there any schedule for the GAE transactions/entity groups ? > > > > > > if not, how would it be the best way (web2py upgrades compatible !) > to > > > > use entity groups and transaction with web2py ? > > > > > > thanks > > > > > > On Jan 19, 2:59 pm, Robin B <[email protected]> wrote: > > > > > > > > Groups under the DAL to be a single record. Since Big Table > > > > > > transactions are limited to one Entity Group pertransaction, this > > > > > > means that we are limited to one record pertransaction. Right? > > > > > > > You have it right. > > > > > > > > In the example above, 'count' is just an example of some > arbitrary > > > > > > column in the record, right? Can I have multiple assignments? Can > I > > > > > > mix lambda and non-lambda assignments? E.g.: > > > > > > > > row.update_record(count=lambda r: r.count+1, > vote_score=lambda r: > > > > > > calculate_vote_score(), preference='blue') > > > > > > > Yes, you would be able to mix lamdas/functions and values. > > > > > > > On the subject of passing lamdas as attributes, the field.default= > > > > > should also recognize any lambda/callable and call it on demand: > > > > > > > def uuid(): > > > > > import uuid > > > > > return uuid.uuid4() > > > > > > > db.table.created_at.default=t2.now > > > > > db.table.uuid.default=uuid > > > > > > > Robin > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "web2py Web Framework" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/web2py?hl=en -~----------~----~----~----~------~----~------~--~---
