object-relational mappers

[Bruno Desthuilliers]

Jarek Zgoda a écrit :
> Bruno Desthuilliers napisał(a):
> 
>> Now my own experience is that whenever I tried this approach for
>> anything non-trivial, I ended up building an "ad-hoc,
>> informally-specified bug-ridden slow implementation of half of "
>> SQLAlchemy. Which BTW is not strictly an ORM, but primarily an attempt
>> at a better integration of SQL into Python. So while it may feel like
>> learning the inner complexities of SQLALchemy (or Django's ORM which is
>> not that bad either) is "wasting brain cells", MVHO is that it's worth
>> the time spent. But YMMV of course - IOW, do what works best for you.
> 
> I like OR mappers, they save me lot of work. The problem is, all of them
> are very resource hungry, processing resultset of 300k objects one by
> one can effectively kill most of commodity systems. This is where raw
> SQL comes in handy.

The problem here is not about how you build your query but about how you 
retrieve your data. FWIW, SQLAlchemy provides quite a lot of "lower 
level" SQL/Python integration that doesn't require the "object mapping" 
part. "raw SQL" is fine, until you have to dynamically build complex 
queries from user inputs and whatnot. This is where the "low-level" (ie: 
non-ORM) part of SQLAlchemy shines IMHO.