Sqlalchemy is great! The more I explore, the more inner beauty of it I realize. On Feb 24, 2014 8:15 AM, "Jonathan Vanasco" <jonat...@findmeon.com> wrote:
> To expand and clarify Simon's answer into bulletpoints : > > Expired Object > * The database Session the object belongs to has been closed ( or > committed unless you tweaked the config ) > * SqlAlchemy considers it 'expired' because it is not reasonable to expect > the object to reflect the current state of the database > * the object must be reloaded from the db or 'merged' into a new session. > > Dirty Object > * There have been changes to attributes on a "Clean" object loaded from > the database > * Changing an attribute , or adding an object, doesn't automatically write > to the database. > * You must explicitly call `flush()` to write the database, or `commit()` > to both write to the database and commit the transaction. > > Overall > * SqlAlchemy is your friend and looks out for you, avoiding common > mistakes: > * It automatically reloads most "Expired Objects" from the database (and > raises an error at other times) so you have the most correct data in the ORM > * It makes you explicitly write to the database when you have new objects > or changes to commit. > > While it could be possible to extend SqlAlchemy to automatically 'write' > to the database when you change an attribute, that would cause a lot of SQL > overhead and probably screw up constraint checks. > > > > > > > -- > You received this message because you are subscribed to a topic in the > Google Groups "sqlalchemy" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/sqlalchemy/tGGrkYX5tlE/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > sqlalchemy+unsubscr...@googlegroups.com. > To post to this group, send email to sqlalchemy@googlegroups.com. > Visit this group at http://groups.google.com/group/sqlalchemy. > For more options, visit https://groups.google.com/groups/opt_out. > -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at http://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/groups/opt_out.
