On 11/09/17 10:38, GMX wrote: > I am using `pony` orm to write a simple class as my model.
pony is not a standard module (indeed I only heard about it from your email) so you are probably best asking on the pony support forum if such exists or via the author. > from pony.orm import Database > from pony.orm import Required, Optional > from pony.orm import db_session > from pony.orm import select, commit > > DB_PATH = ‘db.sqlite’ > > db = Database() > > class Course(db.Entity): > """ > A class to represent a course > """ > title = Required(str, unique=True) > url = Optional(str, unique=True) > thumbnail = Optional(str) > processed = Optional(bool, default=False) > > db.bind(provider='sqlite', filename=DB_PATH, create_db=True) > db.generate_mapping(create_tables=True) > ``` > > Now when I create a Course object like this: > > >>> Course(title=‘A new course’) > > An object is create in the database. I don’t want to have this behaviour, But that's kind of what an ORM does. The whole point of using an ORM is that it translates your objects into database transactions. > but what I want to be doing is create a Course object > and then only commit in the database if the course is > not already available > in the database. Thats very specific to your ORM. There probably are options to do that, but you will need to ask the pony users. -- Alan G Author of the Learn to Program web site http://www.alan-g.me.uk/ http://www.amazon.com/author/alan_gauld Follow my photo-blog on Flickr at: http://www.flickr.com/photos/alangauldphotos _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
