Thank you! I don't disagree: I've been brainstorming how to work it out upfront, but I think I'd need your topological sort to put the mappers in the correct dependency order and since it is legacy support, I'm ok with the non public API and potential consequences.
I had tried prop.do_init() in place of StrategizedProperty.do_init(prop), but it failed. Why??? (would invoke RelationshipProperty.do_init(), but I would have guess that was the correct method instead of StrategizedProperty's) On Mar 5, 11:04 am, Michael Bayer <[email protected]> wrote: > On Mar 5, 2011, at 10:37 AM, Kent wrote: > > > > > Oracle 8 strikes again. But our client's current legacy application > > requires it (until we can get them off the app). > > > Anyway, when Oracle 8 is detected, I wish to convert certain mapper > > properties' lazy attribute from False => 'subquery' because oracle 8 > > isn't smart enough to run the query anywhere near efficiently (but 9i > > is). > > > So, after all the mappers are compiled (I need backrefs also), I'm > > looping through the _mapper_registry and detecting which properties > > need to be converted if the oracle is 8i. > > > Unfortunately for me: > > prop.lazy = 'subquery' > > prop.strategy_class = strategies.factory('subquery') > > > isn't enough because the prop.strategy was already initialized I > > surmise. > > > Because of potential circular references and complications with > > backrefs and future mapped classes not being mapped to a table until > > after mapper() is invoked for the class, I do not think I can figure > > out whether lazy should be False vs. 'subquery' during the mapper() > > invocation...(at least trivially), so I am waiting until after all > > mappers are compiled. > > > Can you think of any solutions for me? Any way to change a properties > > lazy attribute after it's been instantiated? Any way to clone the > > property and replace it with a new one with a difference lazy > > attribute? > > If it were me I'd still try to solve the problem of deciding which > relationships/backrefs need the setting up front. You can limit it to those > who are setting up lazy="joined" I assume, and i'd consider getting ugly too > with some hardcoding, since this is for legacy support anyway. > > Otherwise the internal API magic you need would be: > > from sqlalchemy.orm.interfaces import StrategizedProperty > > prop.strategy_class = strategies.factory('subquery') > StrategizedProperty.do_init(prop) > > which would reset the "self.strategy" attribute and the collection of > alternate strategies. -- You received this message because you are subscribed to the Google Groups "sqlalchemy" 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/sqlalchemy?hl=en.
