import datetime import decimal import unittest from django.db import connection, models from django.db.models.functions import Cast from django.test import TestCase, ignore_warnings, skipUnlessDBFeature from django.test.utils import CaptureQueriesContext from ..models import Author, DTModel, Fan, FloatModel class CastTests(TestCase): @classmethod def setUpTestData(self): Author.objects.create(name='Bob', age=1, alias='1') def test_cast_from_value(self): numbers = Author.objects.annotate(cast_integer=Cast(models.Value('0'), models.IntegerField())) self.assertEqual(numbers.get().cast_integer, 0) def test_cast_from_field(self): numbers = Author.objects.annotate(cast_string=Cast('age', models.CharField(max_length=255)),) self.assertEqual(numbers.get().cast_string, '1') def test_cast_to_char_field_without_max_length(self): numbers = Author.objects.annotate(cast_string=Cast('age', models.CharField())) self.assertEqual(numbers.get().cast_string, '1') # Silence "Truncated incorrect CHAR(1) value: 'Bob'". @ignore_warnings(module='django.db.backends.mysql.base') @skipUnlessDBFeature('supports_cast_with_precision') def test_cast_to_char_field_with_max_length(self): names = Author.objects.annotate(cast_string=Cast('name', models.CharField(max_length=1))) self.assertEqual(names.get().cast_string, 'B') @skipUnlessDBFeature('supports_cast_with_precision') def test_cast_to_decimal_field(self): FloatModel.objects.create(f1=-1.934, f2=3.467) float_obj = FloatModel.objects.annotate( cast_f1_decimal=Cast('f1', models.DecimalField(max_digits=8, decimal_places=2)), cast_f2_decimal=Cast('f2', models.DecimalField(max_digits=8, decimal_places=1)), ).get() self.assertEqual(float_obj.cast_f1_decimal, decimal.Decimal('-1.93')) self.assertEqual(float_obj.cast_f2_decimal, decimal.Decimal('3.5')) author_obj = Author.objects.annotate( cast_alias_decimal=Cast('alias', models.DecimalField(max_digits=8, decimal_places=2)), ).get() self.assertEqual(author_obj.cast_alias_decimal, decimal.Decimal('1')) def test_cast_to_integer(self): for field_class in ( models.AutoField, models.BigAutoField, models.SmallAutoField, models.IntegerField, models.BigIntegerField, models.SmallIntegerField, models.PositiveBigIntegerField, models.PositiveIntegerField, models.PositiveSmallIntegerField, ): with self.subTest(field_class=field_class): numbers = Author.objects.annotate(cast_int=Cast('alias', field_class())) self.assertEqual(numbers.get().cast_int, 1) def test_cast_to_duration(self): duration = datetime.timedelta(days=1, seconds=2, microseconds=3) DTModel.objects.create(duration=duration) dtm = DTModel.objects.annotate( cast_duration=Cast('duration', models.DurationField()), cast_neg_duration=Cast(-duration, models.DurationField()), ).get() self.assertEqual(dtm.cast_duration, duration) self.assertEqual(dtm.cast_neg_duration, -duration) def test_cast_from_db_datetime_to_date(self): dt_value = datetime.datetime(2018, 9, 28, 12, 42, 10, 234567) DTModel.objects.create(start_datetime=dt_value) dtm = DTModel.objects.annotate( start_datetime_as_date=Cast('start_datetime', models.DateField()) ).first() self.assertEqual(dtm.start_datetime_as_date, datetime.date(2018, 9, 28)) def test_cast_from_db_datetime_to_time(self): dt_value = datetime.datetime(2018, 9, 28, 12, 42, 10, 234567) DTModel.objects.create(start_datetime=dt_value) dtm = DTModel.objects.annotate( start_datetime_as_time=Cast('start_datetime', models.TimeField()) ).first() rounded_ms = int(round(.234567, connection.features.time_cast_precision) * 10**6) self.assertEqual(dtm.start_datetime_as_time, datetime.time(12, 42, 10, rounded_ms)) def test_cast_from_db_date_to_datetime(self): dt_value = datetime.date(2018, 9, 28) DTModel.objects.create(start_date=dt_value) dtm = DTModel.objects.annotate(start_as_datetime=Cast('start_date', models.DateTimeField())).first() self.assertEqual(dtm.start_as_datetime, datetime.datetime(2018, 9, 28, 0, 0, 0, 0)) def test_cast_from_db_datetime_to_date_group_by(self): author = Author.objects.create(name='John Smith', age=45) dt_value = datetime.datetime(2018, 9, 28, 12, 42, 10, 234567) Fan.objects.create(name='Margaret', age=50, author=author, fan_since=dt_value) fans = Fan.objects.values('author').annotate( fan_for_day=Cast('fan_since', models.DateField()), fans=models.Count('*') ).values() self.assertEqual(fans[0]['fan_for_day'], datetime.date(2018, 9, 28)) self.assertEqual(fans[0]['fans'], 1) def test_cast_from_python_to_date(self): today = datetime.date.today() dates = Author.objects.annotate(cast_date=Cast(today, models.DateField())) self.assertEqual(dates.get().cast_date, today) def test_cast_from_python_to_datetime(self): now = datetime.datetime.now() dates = Author.objects.annotate(cast_datetime=Cast(now, models.DateTimeField())) time_precision = datetime.timedelta( microseconds=10**(6 - connection.features.time_cast_precision) ) self.assertAlmostEqual(dates.get().cast_datetime, now, delta=time_precision) def test_cast_from_python(self): numbers = Author.objects.annotate(cast_float=Cast(decimal.Decimal(0.125), models.FloatField())) cast_float = numbers.get().cast_float self.assertIsInstance(cast_float, float) self.assertEqual(cast_float, 0.125) @unittest.skipUnless(connection.vendor == 'postgresql', 'PostgreSQL test') def test_expression_wrapped_with_parentheses_on_postgresql(self): """ The SQL for the Cast expression is wrapped with parentheses in case it's a complex expression. """ with CaptureQueriesContext(connection) as captured_queries: list(Author.objects.annotate( cast_float=Cast(models.Avg('age'), models.FloatField()), )) self.assertIn( '(AVG("db_functions_author"."age"))::double precision', captured_queries[0]['sql'], ) def test_cast_to_text_field(self): self.assertEqual(Author.objects.values_list(Cast('age', models.TextField()), flat=True).get(), '1')