> That is, in my case, lifetime of objects is much longer that > lifetime of all database-and-related stuff - and seems this is not > expected pattern of usage.
more questions on the theme. What is the expected sequence / lifetime / pattern-of-usage for engine, metadata, mappers, and finally, my objects? This is also related to multiplicity, e.g. can i have several metadatas, and switch between them for same objects. The only obvious rule i see is that a) mappers must be made after metadata; not sure if that being unbound is allowed. The other rule inferred from above problem is b) objects lifetime should be shorter than mappers (ORM); else one needs to delete o._instance_key and o.db_id to be able to reuse them Are there other rules? i do remember about doing mappers over unbound metadata and binding later did break certain cases. e.g. default is: 1.make engine 2.make metadata + .create_all() 3.make mappers 4.objects can i do: 1. make metadata /unbound 2. mappers 3. make engine 4. bind metadata + .create_all() 5. objects then unbind metadata/drop engine, then repeat 3,4,5 ? or 1. engine 2. metadata 3. mappers 4. objects 5 metadata.drop_all() + metadata.create_all() 6 more objects repeat 5,6 or (current links/nodes case) 1. objects 2. engine 3. metadata + createall() 4. mappers 5. drop everything repeat 2,3,4,5 ... or (probably better way of doing it, make type-info stuff once) 1. engine 2. metadata + createall() 3. mappers 4. objects 5. metadata.drop_all() + metadata.create_all() 6. save same objects repeat 5,6 svil --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalchemy@googlegroups.com 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 -~----------~----~----~----~------~----~------~--~---
