Hi, >As long as you never use GROUP BY/DISTINCT, or aggregate functions, or >non-trivial joins, SQLObject and friends work just fine. > I do use GROUP BY with an ORM successfully. In SQL, group by is mostly (only?) useful when you're using an aggregate function. With an ORM, at that point, the objects represented by the rows are different object to the underlying table. So I create a specific class for this and map it to the select.
Say you have a customer_value table with fields customer_id, region_id and value. You want to look at the total value in a region (I was about to say best customer, but that's actually tricky sql-wise). The query is select region_id, sum(value) from customer_value group by value. So, map that to RegionValue, and you can then use that as a normal class, e.g. RegionValue.query.get(77) You can even create relationships to your region table, so doing Region.get(77).value would actually compute the total value in SQL (although strictly that doesn't need group by). DISTINCT doesn't really work with an ORM - because everything has an identity, everything is distinct already. There's still some benefit to using SQLAlchemy in non-ORM mode - queries are shorter as they leverage the relations defined in the model, and you can mix python values more freely into the query, without bind params and such. Paul --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "TurboGears" 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/turbogears?hl=en -~----------~----~----~----~------~----~------~--~---
