On Sun, Feb 26, 2017 at 5:05 PM, <[email protected]> wrote: > > > On Sunday, February 26, 2017 at 12:55:17 PM UTC+1, Daniel Roseman wrote: >> >> >> You should explain what you want to achieve. Grouping is pointless on its >> own. In any case, when working with an ORM like Django's it is generally not >> helpful to think in terms of SQL. >> -- >> DR. > > > Also forget window functions, triggers, conditionals, pubsub and many other > great db features, just because of Django ORM... > > Daniel is right - Django ORM will limit your expressions, but not every ORM > works that way. SQLAlchemy, in contrast, allows you not only grouping, but > also wrap anything into their expression API. > > With Django there is still possibility to do raw queries, nby > Model.objects.raw(). I'm doing a complex queries that way, but I'm avoiding > spaghetti code by using django-sqltemplate. It allows you to write big SQLs > in separate files (also as templates),load using Django templates engine, > and finally pass the result directly to Model.objects.raw(), if you want. > > You can force grouping, AFAIR. Try to get query object from your queryset, > i.e. q=Model.objects.all().query and play with q.group_by or something like > that. But this is kind of nasty workaround. I would not recommend doing > grouping that way in a project with long-term support. > > Generally speaking Django ORM is quite simple, limited and does not work > well for more complex projects. I don't want to talk more about this, > because my point of view is generally opposite to the "Django Way" (tm). I > can just say that I'm using Django ORM as simple mapper for most typical > cases, leaving more complex things for better tools. > > And, Larry, please never give up and always think about db and data first, > then about application layer. Data is most important. It's lifetime is much > longer than any app. Continue thinking about grouping, windowing, indexing, > fts and so on, and find a way how to handle such things using tools like > Django.
I agree with Marcin. The ORM is a tool and the tool should serve its user, not the other way around. I have an app that has been developed and deployed over 7 years. At the beginning it only used the ORM. But over time, due to performance issues, and application requirements, we've had to move to raw SQL more and more. -- You received this message because you are subscribed to the Google Groups "Django users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/django-users. To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/CACwCsY66HhECopa0xOHYJ3n_t-17-OZ7dfTFWOvB7BUK_3_Zmw%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
