Fixed #24629 -- Unified Transform and Expression APIs

django/contrib/postgres/fields/hstore.py

@@ -81,14 +81,14 @@ def __call__(self, *args, **kwargs):
 
 
 @HStoreField.register_lookup
-class KeysTransform(lookups.FunctionTransform):
+class KeysTransform(Transform):
     lookup_name = 'keys'
     function = 'akeys'
     output_field = ArrayField(TextField())
 
 
 @HStoreField.register_lookup
-class ValuesTransform(lookups.FunctionTransform):
+class ValuesTransform(Transform):
     lookup_name = 'values'
     function = 'avals'
     output_field = ArrayField(TextField())

django/contrib/postgres/fields/ranges.py

@@ -173,7 +173,7 @@ class AdjacentToLookup(lookups.PostgresSimpleLookup):
 
 
 @RangeField.register_lookup
-class RangeStartsWith(lookups.FunctionTransform):
+class RangeStartsWith(models.Transform):
     lookup_name = 'startswith'
     function = 'lower'
 
@@ -183,7 +183,7 @@ def output_field(self):
 
 
 @RangeField.register_lookup
-class RangeEndsWith(lookups.FunctionTransform):
+class RangeEndsWith(models.Transform):
     lookup_name = 'endswith'
     function = 'upper'
 
@@ -193,7 +193,7 @@ def output_field(self):
 
 
 @RangeField.register_lookup
-class IsEmpty(lookups.FunctionTransform):
+class IsEmpty(models.Transform):
     lookup_name = 'isempty'
     function = 'isempty'
     output_field = models.BooleanField()

django/contrib/postgres/lookups.py

@@ -9,12 +9,6 @@ def as_sql(self, qn, connection):
         return '%s %s %s' % (lhs, self.operator, rhs), params
 
 
-class FunctionTransform(Transform):
-    def as_sql(self, qn, connection):
-        lhs, params = qn.compile(self.lhs)
-        return "%s(%s)" % (self.function, lhs), params
-
-
 class DataContains(PostgresSimpleLookup):
     lookup_name = 'contains'
     operator = '@>'
@@ -45,7 +39,7 @@ class HasAnyKeys(PostgresSimpleLookup):
     operator = '?|'
 
 
-class Unaccent(FunctionTransform):
+class Unaccent(Transform):
     bilateral = True
     lookup_name = 'unaccent'
     function = 'UNACCENT'

django/db/models/fields/__init__.py

@@ -20,10 +20,7 @@
 # purposes.
 from django.core.exceptions import FieldDoesNotExist  # NOQA
 from django.db import connection, connections, router
-from django.db.models.lookups import (
-    Lookup, RegisterLookupMixin, Transform, default_lookups,
-)
-from django.db.models.query_utils import QueryWrapper
+from django.db.models.query_utils import QueryWrapper, RegisterLookupMixin
 from django.utils import six, timezone
 from django.utils.datastructures import DictWrapper
 from django.utils.dateparse import (
@@ -120,7 +117,6 @@ class Field(RegisterLookupMixin):
         'unique_for_date': _("%(field_label)s must be unique for "
                              "%(date_field_label)s %(lookup_type)s."),
     }
-    class_lookups = default_lookups.copy()
     system_check_deprecated_details = None
     system_check_removed_details = None
 
@@ -1492,22 +1488,6 @@ def formfield(self, **kwargs):
         return super(DateTimeField, self).formfield(**defaults)
 
 
-@DateTimeField.register_lookup
-class DateTimeDateTransform(Transform):
-    lookup_name = 'date'
-
-    @cached_property
-    def output_field(self):
-        return DateField()
-
-    def as_sql(self, compiler, connection):
-        lhs, lhs_params = compiler.compile(self.lhs)
-        tzname = timezone.get_current_timezone_name() if settings.USE_TZ else None
-        sql, tz_params = connection.ops.datetime_cast_date_sql(lhs, tzname)
-        lhs_params.extend(tz_params)
-        return sql, lhs_params
-
-
 class DecimalField(Field):
     empty_strings_allowed = False
     default_error_messages = {
@@ -2450,146 +2430,3 @@ def formfield(self, **kwargs):
         }
         defaults.update(kwargs)
         return super(UUIDField, self).formfield(**defaults)
-
-
-class DateTransform(Transform):
-    def as_sql(self, compiler, connection):
-        sql, params = compiler.compile(self.lhs)
-        lhs_output_field = self.lhs.output_field
-        if isinstance(lhs_output_field, DateTimeField):
-            tzname = timezone.get_current_timezone_name() if settings.USE_TZ else None
-            sql, tz_params = connection.ops.datetime_extract_sql(self.lookup_name, sql, tzname)
-            params.extend(tz_params)
-        elif isinstance(lhs_output_field, DateField):
-            sql = connection.ops.date_extract_sql(self.lookup_name, sql)
-        elif isinstance(lhs_output_field, TimeField):
-            sql = connection.ops.time_extract_sql(self.lookup_name, sql)
-        else:
-            raise ValueError('DateTransform only valid on Date/Time/DateTimeFields')
-        return sql, params
-
-    @cached_property
-    def output_field(self):
-        return IntegerField()
-
-
-class YearTransform(DateTransform):
-    lookup_name = 'year'
-
-
-class YearLookup(Lookup):
-    def year_lookup_bounds(self, connection, year):
-        output_field = self.lhs.lhs.output_field
-        if isinstance(output_field, DateTimeField):
-            bounds = connection.ops.year_lookup_bounds_for_datetime_field(year)
-        else:
-            bounds = connection.ops.year_lookup_bounds_for_date_field(year)
-        return bounds
-
-
-@YearTransform.register_lookup
-class YearExact(YearLookup):
-    lookup_name = 'exact'
-
-    def as_sql(self, compiler, connection):
-        # We will need to skip the extract part and instead go
-        # directly with the originating field, that is self.lhs.lhs.
-        lhs_sql, params = self.process_lhs(compiler, connection, self.lhs.lhs)
-        rhs_sql, rhs_params = self.process_rhs(compiler, connection)
-        bounds = self.year_lookup_bounds(connection, rhs_params[0])
-        params.extend(bounds)
-        return '%s BETWEEN %%s AND %%s' % lhs_sql, params
-
-
-class YearComparisonLookup(YearLookup):
-    def as_sql(self, compiler, connection):
-        # We will need to skip the extract part and instead go
-        # directly with the originating field, that is self.lhs.lhs.
-        lhs_sql, params = self.process_lhs(compiler, connection, self.lhs.lhs)
-        rhs_sql, rhs_params = self.process_rhs(compiler, connection)
-        rhs_sql = self.get_rhs_op(connection, rhs_sql)
-        start, finish = self.year_lookup_bounds(connection, rhs_params[0])
-        params.append(self.get_bound(start, finish))
-        return '%s %s' % (lhs_sql, rhs_sql), params
-
-    def get_rhs_op(self, connection, rhs):
-        return connection.operators[self.lookup_name] % rhs
-
-    def get_bound(self):
-        raise NotImplementedError(
-            'subclasses of YearComparisonLookup must provide a get_bound() method'
-        )
-
-
-@YearTransform.register_lookup
-class YearGt(YearComparisonLookup):
-    lookup_name = 'gt'
-
-    def get_bound(self, start, finish):
-        return finish
-
-
-@YearTransform.register_lookup
-class YearGte(YearComparisonLookup):
-    lookup_name = 'gte'
-
-    def get_bound(self, start, finish):
-        return start
-
-
-@YearTransform.register_lookup
-class YearLt(YearComparisonLookup):
-    lookup_name = 'lt'
-
-    def get_bound(self, start, finish):
-        return start
-
-
-@YearTransform.register_lookup
-class YearLte(YearComparisonLookup):
-    lookup_name = 'lte'
-
-    def get_bound(self, start, finish):
-        return finish
-
-
-class MonthTransform(DateTransform):
-    lookup_name = 'month'
-
-
-class DayTransform(DateTransform):
-    lookup_name = 'day'
-
-
-class WeekDayTransform(DateTransform):
-    lookup_name = 'week_day'
-
-
-class HourTransform(DateTransform):
-    lookup_name = 'hour'
-
-
-class MinuteTransform(DateTransform):
-    lookup_name = 'minute'
-
-
-class SecondTransform(DateTransform):
-    lookup_name = 'second'
-
-
-DateField.register_lookup(YearTransform)
-DateField.register_lookup(MonthTransform)
-DateField.register_lookup(DayTransform)
-DateField.register_lookup(WeekDayTransform)
-
-TimeField.register_lookup(HourTransform)
-TimeField.register_lookup(MinuteTransform)
-TimeField.register_lookup(SecondTransform)
-
-DateTimeField.register_lookup(YearTransform)
-DateTimeField.register_lookup(MonthTransform)
-DateTimeField.register_lookup(DayTransform)
-DateTimeField.register_lookup(WeekDayTransform)
-DateTimeField.register_lookup(HourTransform)
-DateTimeField.register_lookup(MinuteTransform)
-DateTimeField.register_lookup(SecondTransform)

django/db/models/functions.py

@@ -1,8 +1,9 @@
 """
 Classes that represent database functions.
 """
-from django.db.models import DateTimeField, IntegerField
-from django.db.models.expressions import Func, Value
+from django.db.models import (
+    DateTimeField, Func, IntegerField, Transform, Value,
+)
 
 
 class Coalesce(Func):
@@ -123,9 +124,10 @@ def as_sqlite(self, compiler, connection):
         return super(Least, self).as_sql(compiler, connection, function='MIN')
 
 
-class Length(Func):
+class Length(Transform):
     """Returns the number of characters in the expression"""
     function = 'LENGTH'
+    lookup_name = 'length'
 
     def __init__(self, expression, **extra):
         output_field = extra.pop('output_field', IntegerField())
@@ -136,8 +138,9 @@ def as_mysql(self, compiler, connection):
         return super(Length, self).as_sql(compiler, connection)
 
 
-class Lower(Func):
+class Lower(Transform):
     function = 'LOWER'
+    lookup_name = 'lower'
 
     def __init__(self, expression, **extra):
         super(Lower, self).__init__(expression, **extra)
@@ -188,8 +191,9 @@ def as_oracle(self, compiler, connection):
         return super(Substr, self).as_sql(compiler, connection)
 
 
-class Upper(Func):
+class Upper(Transform):
     function = 'UPPER'
+    lookup_name = 'upper'
 
     def __init__(self, expression, **extra):
         super(Upper, self).__init__(expression, **extra)