On Apr 14, 2011, at 9:36 AM, bool wrote: > > Thanks Michael Trier. > > > Michael Bayer, > > Can you help me with the other two questions I asked ?
yes but I would note that lots of people on this list are capable of answering these questions. Am trying to slow my responses so that others can more easily participate. > Why does mapper cache for update/insert/delete This is to improve performance. update/delete statements emitted during the flush are strictly against primary key identity and possibly a version id column and there's no use case for modifying the WHERE criterion ad hoc within a flush. An update that uses a WHERE against fluid criterion is more appropriate in the query.update() use case, where the previous recipe I gave would still work. > and can you confirm it > does not do this for select and I can safely use this approach for > select with ORM? selects aren't cached. The only caching with query comes into play when you use get() - it will fetch the given identity from the identity map if present. > Is there a recipe/code which I can quickly refer to get started on > before_insert and also how to modify a insert statement in > before_insert? there's a short example of before_insert right here: http://www.sqlalchemy.org/docs/orm/interfaces.html#mapper-events -- 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.
