Hello there. I'm using SA-0.7 to develop an application that should help me manage my company's services.
A central concept here is the order, it could be a service (like one year of web hosting) or a physical item (like a pc we sell). So far I generalized them in two classes: the Order and the ServiceOrder - the latter simply inherits the former and adds start and end dates. Now I need to add all various kinds of metadata to orders, for example: - a ServiceOrder for a domain hosting should contain the domain name - a ServiceOrder for a maintenance service should contain the service level for that service (say, basic or advanced) - an Order for a PC we delivered should contain its serial number - and so on... I could easily add child classes, but that would mean to keep and maintain that code forever even after we stop using it (ie, next year we stop doing hosting) or when it's not really useful (many things will just have some 'metadata' in them like a serial number or similar things). I'd also like to avoid having to add code every time we just hit something slightly different to manage, when we just have some additional data to keep track of. I wonder what could be an intelligent approach to such a situation. One idea I got could be to add an 'OrderTags' table / class that would associate (tag, value) tuples to my orders, and somehow access them like a dictionary (eg. Order.tags['serialnumber'] = 'foo' or ServiceOrder.tags['domainname'] = 'example.com'). But that will probably keep them out of standard SA queries? For example, if I want to retrieve the full history of a domain we're hosting, how could I query for all orders with (tags['domainname'] == something)? I'm looking for advice on how to structure this data, and how to best implement it with python and sqlalchemy-0.7. Thank you, Luca -- 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 sqlalchemy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.
