#9368: Clean up code for getting columns for select query ------------------------------------------+--------------------------------- Reporter: adunar | Owner: nobody Status: new | Milestone: post-1.0 Component: Database layer (models, ORM) | Version: Keywords: | Stage: Unreviewed Has_patch: 1 | ------------------------------------------+--------------------------------- I cleaned up some code in db/models/sql/query.py (see mtredinnick's suggestion on http://code.djangoproject.com/ticket/5420)
In particular: * The code to get a column's SQL alias was duplicated in 6 places, so I factored that out into a function * Depending on whether the get_default_columns function was called for the base model or a related model, it took different parameters, did different things, and returned different values. So I split it into two separate functions, get_base_columns and get_related_columns. This refactoring makes the Query class easier to understand and easier to subclass with less code duplication. * I added a function Query.get_base_fields, which the !QuerySet class uses to determine which fields correspond to the values from the result set. Currently, get_base_fields returns all fields of the base model. However, Query subclasses could potentially override get_base_fields (as well as get_base_columns) so that only a subset of the model's fields are returned (e.g. if you want to lazy-load some large fields). A large motivation for this refactoring is that functional decomposition of get_columns made it difficult to subclass Query to provide custom behavior. This can be seen especially well in contrib.gis.db.models.query, where it needed to override a small bit of logic in the middle of get_columns and get_default_columns, but ended up having to copy and paste those entire functions (which were both quite large) as a result. My change at least makes it so gis doesn't have to copy and paste quite as much. I would have liked to not copy and paste anything in gis, but I didn't quite figure out how to do that without breaking the regression tests. (Also, I haven't even run the code in gis because I don't have the necessary libraries installed. So somebody else might want to test that part...) -- Ticket URL: <http://code.djangoproject.com/ticket/9368> Django <http://code.djangoproject.com/> The Web framework for perfectionists with deadlines. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django updates" group. To post to this group, send email to django-updates@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-updates?hl=en -~----------~----~----~----~------~----~------~--~---
