Fixed #24020 -- Refactored SQL compiler to use 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.

1 files changed, 2 insertions, 2 deletions

diff --git a/django/db/backends/__init__.py b/django/db/backends/__init__.py
index 3c99819218..6c675cb482 100644
--- a/django/db/backends/__init__.py
+++ b/django/db/backends/__init__.py
@@ -1262,7 +1262,7 @@ class BaseDatabaseOperations(object):
             second = timezone.make_aware(second, tz)
         return [first, second]
 
-    def get_db_converters(self, internal_type):
+    def get_db_converters(self, expression):
         """Get a list of functions needed to convert field data.
 
         Some field types on some backends do not provide data in the correct
@@ -1270,7 +1270,7 @@ class BaseDatabaseOperations(object):
         """
         return []
 
-    def convert_durationfield_value(self, value, field):
+    def convert_durationfield_value(self, value, expression, context):
         if value is not None:
             value = str(decimal.Decimal(value) / decimal.Decimal(1000000))
             value = parse_duration(value)