The new DAL structure (which you can see in gluon/dal.py) has a standard API (DAL, Table, Field, etc) and delegates everything to an adapter. There are adapters for all supported RDBS (CPython and Jython) and there will be some for NODB as well. Adapters have a hierarchical structure that basically implement what you suggested.
Massimo On Jan 3, 8:01 pm, Yarko Tymciurak <resultsinsoftw...@gmail.com> wrote: > On Jan 3, 12:19 pm, mdipierro <mdipie...@cs.depaul.edu> wrote: > > > I agree. I think there should be a web2py type that merges the > > functionalities of ListProperty on GAE and IS_IN_SET(multiple=True) > > This is one instance of what I imagined has to happen when (some time > ago) I mentioned that potentially there would be a separate DAL for > non-RDB stores e.g. MongoDB [C++ -http://www.mongodb.org], couchDB > [Erlang -http://couchdb.apache.org/], Amazon SimpleDB [http:// > aws.amazon.com/simpledb/ - compare w/http://aws.amazon.com/s3] are > listed as document-oreinted on Wikipedia; > > GAE - if you follow WIkipedia correlations - is of a class with > Hypertable, Cassandra [Facebook:Java -http://incubator.apache.org/cassandra/], > and Project Voldemort [Linkedin:Java -http://project-voldemort.com/], > and Hadoop [Yahoo search:Java -http://hadoop.apache.org/]). > > Some things are beginning to become clear about all these cloud > computing vs. storage technology strategies & evolutions - while some > may favor one, they are loosely coupled, so I expect that what serves > the application will take precedence over how that can get implemented > on the cloud (GAE / Big Tables seems to be the cloud image of shared > hosting: you get to run what they provide - java & python in this case > - and use the "db" they have installed - big tables in this case; > Amazon services seem generally closer to a virtualized hosting, with > simpleDB being a nod to a "db" kind of storage app, pre-canned). > > I don't think this realization (cloud analogies) should affect much > about DAL evolution: GAE etc. should still be mined for conceptual > similarities, and over time decisions should emerge about what is > worth making portable - e.g. depending on backend, letting backend > facility be accessed, or do / abstract something similar in > framework. DAL will thus help equalize / cross-polinate; this should > be only with the _really_ useful or needed concepts. > > </end random thoughts> > - Yarko > > > > > On Jan 3, 11:52 am, Yarko Tymciurak <resultsinsoftw...@gmail.com> > > wrote: > > > > This is directly obvious, but I will state it anyway: > > > > On Dec 30 2009, 1:17 am, mdipierro <mdipie...@cs.depaul.edu> wrote: > > > > > I changed this. It was UGLY. > > > > > Now you can do: > > > > > from gluon.contrib.gql import gae > > > > db.define_table('person',Field('names',gae.StringListProperty())) > > > > for a DAL (abstraction layer), this is tied to _one_ persistence store > > > (the string method was not). > > > > The good part of this (from a programmer's perspective) is that it is > > > explicit - you know "StingListProperty" is intended to be a gae thing; > > > > The bad part: it erodes the concept of portability, the prime goal of > > > DAL ... > > > > It may be useful for the moment, but there is a design tension which > > > is begging for a more comfortable resolution ... > > > > > and you can do: > > > > > db.person.insert(names=['Massimo','Max']) > > > > db(db.person.names=='Massimo').select() > > > > > So you can use any native google type AND you can make your own. > > > > Perhaps you can say a little more on "... and you can make your > > > own."? > > > > Thanks, > > > - Yarko > > > > > Massimo > > > > > On Dec 30, 12:50 am, mdipierro <mdipie...@cs.depaul.edu> wrote: > > > > > > There are many GAE types that one may want to use. Today I needed > > > > > StringListProperty so I extended the web2py GAE apy so that you can > > > > > have a field of type > > > > > > db.define_table('person',Field('names','.StringListProperty()')) > > > > > > and you can do > > > > > > db.person.insert(names=['Massimo','Max']) > > > > > db(db.person.names=='Massimo').select() > > > > > > Basically you can put any native type as a web2py type just put it in > > > > > a string and start it with a '.'. You can also pass arguments this > > > > > way. > > > > > > It is ugly but works. It is ugly because I'd rather pass an object > > > > > than a string. It works because a type has to be a string. It is > > > > > experimental because when the new DAL comes this should be replaced by > > > > > a better API. This will not stay backward compatible. > > > > > > Massimo- Hide quoted text - > > > > - Show quoted text - > > -- You received this message because you are subscribed to the Google Groups "web2py-users" group. To post to this group, send email to web...@googlegroups.com. To unsubscribe from this group, send email to web2py+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/web2py?hl=en.
