Valuable advice. Your assessment of my understanding of the ORM was quite correct. That, plus I was working from the TurboGears book which didn't indicate that I could divorce myself from the ORM, combined with the general trend towards SQLAlchemy on this list. But now it sounds like I don't need the ORM's, and as a few of you have noticed, I certainly don't want them.
Thanks all. On Dec 5, 2007 12:22 PM, Diez B. Roggisch <[EMAIL PROTECTED]> wrote: > Most of the problems people have with ORMs stem from them not really buying > into it, but instead thinking (as you seem to do) "I know about SQL, I know > about objects - now this ORM thingy will allow me to combine both, adding the > featuresets". That is not the case. > > ORM allows you to use objects and persist them without you bothering about the > creation of DDL and SQL. With the cost of not being able to fine-tune both of > them. Usually, they impose constraints like "every row has a unique ID which > corresponds to my object" to the data model, to allow for easy relationship > management. They don't work proper with triggers, stored procedures, > multi-column-primary-keys. > > But ORMs fall flat on their face if what you do is expose all of the > relational modelling and querying SQL allows you. They don't know how to > handle several rows represented by one object - as you want them to. They > fetch all columns or lazily one after another, or all together - which makes > some people shudder. And they don't allow for arbitrary gathering of columns > from joined tables. > > I'm a SO-user, for a mid-sized TG-app with a fairly elaborate data model - > some twenty classes or so. I _never_ hit a real road-block with SO. I'm just > happily coding away in Python, no bother what SQL will result from that. > > And thus it saves me tremendous amounts of time when designing the app. > Granted, when I refactor later in the product cycle, I have to get dirty and > write my table altering statements. But at least for testing & coding, I > don't bother the DB a single second. > > But as others also already pointed out: TG doesn't impose an ORM layer on you. > The newest 1.0.4 beta doesn't even install one anymore. Just point your app > to a DB and get happy. but do yourself a favor - either embrace ORM, or keep > away from it - shoehorning it into generating the SQL you believe ist best > (and actually might be - the question is: how much worse is going the ORM > way) won't make you happy - as you seem to notice :) > > Diez --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
