As suggested by Anssi. This has the slightly strange side effect of
passing the expression to Expression.convert_value has the expression
passed back to it, but it allows more complex patterns of expressions.
Refactored compiler SELECT, GROUP BY and ORDER BY generation.
While there, also refactored select_related() implementation
(get_cached_row() and get_klass_info() are now gone!).
Made get_db_converters() method work on expressions instead of
internal_type. This allows the backend converters to target
specific expressions if need be.
Added query.context, this can be used to set per-query state.
Also changed the signature of database converters. They now accept
context as an argument.
Complete rework of translating data values from database
Deprecation of SubfieldBase, removal of resolve_columns and
convert_values in favour of a more general converter based approach and
public API Field.from_db_value(). Now works seamlessly with aggregation,
.values() and raw queries.
Thanks to akaariai in particular for extensive advice and inspiration,
also to shaib, manfre and timograham for their reviews.
This monster of a patch is the result of Alex Gaynor's 2009 Google Summer of Code project.
Congratulations to Alex for a job well done.
Big thanks also go to:
* Justin Bronn for keeping GIS in line with the changes,
* Karen Tracey and Jani Tiainen for their help testing Oracle support
* Brett Hoerner, Jon Loyens, and Craig Kimmerer for their feedback.
* Malcolm Treddinick for his guidance during the GSoC submission process.
* Simon Willison for driving the original design process
* Cal Henderson for complaining about ponies he wanted.
... and everyone else too numerous to mention that helped to bring this feature into fruition.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@11952 bcc190cf-cafb-0310-a4f2-bffc1f526a37
* Laid foundations for SpatiaLite support in `GeoQuerySet`, `GeoWhereNode` and the tests.
* Added the `Collect` aggregate for PostGIS (still needs tests).
* Oracle now goes to 11.
* The backend-specific `SpatialRefSys` and `GeometryColumns` models are now attributes of `SpatialBackend`.
* Renamed `GeometryField` attributes to be public that were private (e.g., `_srid` -> `srid` and `_geom` -> `geom_type`).
* Renamed `create_test_db` to `create_test_spatial_db`.
* Removed the legacy classes `GeoMixin` and `GeoQ`.
* Removed evil `\` from spatial backend fields.
* Moved shapefile data from `tests/layermap` to `tests/data`.
Fixed#9794. Refs #9686.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@10197 bcc190cf-cafb-0310-a4f2-bffc1f526a37