Ticket #25556: expressions.diff

django/db/models/expressions.py

@@ -892 +892 @@
         return value
 
 
+class DatePart(Date):
+    """
+    Add a partial date selection column.
+
+    Enables construction of complex date queries
+    involving date fields with lookup types of:
+    'year', 'month', 'day'. E.g.:
+
+    `MyModel.objects.filter(date1__month=DatePart('date2', 'month')`
+    """
+    def as_sql(self, compiler, connection):
+        sql, params = self.col.as_sql(compiler, connection)
+        assert not(params)
+        return connection.ops.date_extract_sql(self.lookup_type, sql), []
+
+
 class DateTime(Expression):
     """
     Add a datetime selection column.
@@ -950 +966 @@
         return value
 
 
+class DateTimePart(DateTime):
+    """
+    Add a partial datetime selection column.
+
+    Enables construction of complex date queries
+    involving datetime fields with lookup types of:
+    'year', 'month', 'day'. E.g.:
+
+    `MyModel.objects.filter(date1__month=DatePart('date2', 'month')`
+    """
+    def as_sql(self, compiler, connection):
+        sql, params = self.col.as_sql(compiler, connection)
+        assert not(params)
+        return connection.ops.datetime_extract_sql(self.lookup_type, sql, self.tzname)
+
+
 class OrderBy(BaseExpression):
     template = '%(expression)s %(ordering)s'
 

tests/expressions/tests.py

@@ -11 +11 @@
     Avg, Count, Max, Min, StdDev, Sum, Variance,
 )
 from django.db.models.expressions import (
-    F, Case, Col, Date, DateTime, ExpressionWrapper, Func, OrderBy, Random,
-    RawSQL, Ref, Value, When,
+    F, Case, Col, Date, DatePart, DateTime, DateTimePart, ExpressionWrapper,
+    Func, OrderBy, Random, RawSQL, Ref, Value, When,
 )
 from django.db.models.functions import (
     Coalesce, Concat, Length, Lower, Substr, Upper,
@@ -897 +897 @@
         self.assertEqual(UUID.objects.get().uuid, uuid.UUID('12345678901234567890123456789012'))
 
 
+class DatePartTests(TestCase):
+
+    def setUp(self):
+        self.same_month_day = Experiment.objects.create(
+            name='same_month_day_experiment',
+            assigned=datetime.date(2014, 10, 15),
+            completed=datetime.date(2015, 10, 15),
+            estimated_time=datetime.timedelta(days=1),
+            start=datetime.datetime.now(),
+            end=datetime.datetime.now(),
+        )
+
+        self.same_month = Experiment.objects.create(
+            name='same_month_experiment',
+            assigned=datetime.date(2014, 10, 1),
+            completed=datetime.date(2015, 10, 12),
+            estimated_time=datetime.timedelta(days=1),
+            start=datetime.datetime.now(),
+            end=datetime.datetime.now(),
+        )
+
+        self.same_day = Experiment.objects.create(
+            name='same_day_experiment',
+            assigned=datetime.date(2013, 7, 15),
+            completed=datetime.date(2015, 10, 15),
+            estimated_time=datetime.timedelta(days=1),
+            start=datetime.datetime.now(),
+            end=datetime.datetime.now(),
+        )
+
+    def test_datepart(self):
+        same_day_experiments = Experiment.objects.filter(assigned__day=DatePart('completed', 'day'))
+
+        self.assertEqual(same_day_experiments.count(), 2)
+        self.assertIn(self.same_day, same_day_experiments)
+        self.assertIn(self.same_month_day, same_day_experiments)
+
+        same_month_experiments = Experiment.objects.filter(assigned__month=DatePart('completed', 'month'))
+
+        self.assertEqual(same_month_experiments.count(), 2)
+        self.assertIn(self.same_month, same_month_experiments)
+        self.assertIn(self.same_month_day, same_month_experiments)
+
+        same_month_day_experiment = Experiment.objects.get(
+            assigned__day=DatePart('completed', 'day'),
+            assigned__month=DatePart('completed', 'month'),
+        )
+
+        self.assertEqual(self.same_month_day, same_month_day_experiment)
+
+
+class DateTimePartTests(TestCase):
+
+    def setUp(self):
+        self.same_month_day = Experiment.objects.create(
+            name='same_month_day_experiment',
+            assigned=datetime.date.today(),
+            completed=datetime.date.today(),
+            estimated_time=datetime.timedelta(days=1),
+            start=datetime.datetime(2014, 7, 4, 12, 33, 15),
+            end=datetime.datetime(2015, 7, 4, 10, 13, 12),
+        )
+
+        self.same_month = Experiment.objects.create(
+            name='same_month_experiment',
+            assigned=datetime.date.today(),
+            completed=datetime.date.today(),
+            estimated_time=datetime.timedelta(days=1),
+            start=datetime.datetime(2014, 6, 12, 7, 33, 15),
+            end=datetime.datetime(2015, 6, 5, 11, 13, 12),
+        )
+
+        self.same_day = Experiment.objects.create(
+            name='same_day_experiment',
+            assigned=datetime.date.today(),
+            completed=datetime.date.today(),
+            estimated_time=datetime.timedelta(days=1),
+            start=datetime.datetime(2014, 10, 6, 4, 33, 15),
+            end=datetime.datetime(2015, 3, 6, 1, 13, 12),
+        )
+
+    def test_datetimepart(self):
+        same_day_experiments = Experiment.objects.filter(start__day=DateTimePart('end', 'day'))
+
+        self.assertEqual(same_day_experiments.count(), 2)
+        self.assertIn(self.same_day, same_day_experiments)
+        self.assertIn(self.same_month_day, same_day_experiments)
+
+        same_month_experiments = Experiment.objects.filter(start__month=DateTimePart('end', 'month'))
+
+        self.assertEqual(same_month_experiments.count(), 2)
+        self.assertIn(self.same_month, same_month_experiments)
+        self.assertIn(self.same_month_day, same_month_experiments)
+
+        same_month_day_experiment = Experiment.objects.get(
+            start__day=DatePart('end', 'day'),
+            start__month=DatePart('end', 'month'),
+        )
+
+        self.assertEqual(self.same_month_day, same_month_day_experiment)
+
+
 class ReprTests(TestCase):
 
     def test_expressions(self):