Fixed #22738 -- made finer distinctions for when Boolean is not detected on Oracle

Thanks Claude Paroz for partial fix and Simon Charrette for review

django/db/backends/__init__.py

@@ -614,9 +614,6 @@ class BaseDatabaseFeatures(object):
     # Can the backend introspect an BinaryField, instead of an TextField?
     can_introspect_binary_field = True
 
-    # What is the type returned when the backend introspect a BooleanField?
-    introspected_boolean_field_type = 'BooleanField'
-
     # Can the backend introspect an DecimalField, instead of an FloatField?
     can_introspect_decimal_field = True
 
@@ -715,6 +712,23 @@ class BaseDatabaseFeatures(object):
         except NotImplementedError:
             return False
 
+    def introspected_boolean_field_type(self, field=None, created_separately=False):
+        """
+        What is the type returned when the backend introspects a BooleanField?
+        The optional arguments may be used to give further details of the field to be
+        introspected; in particular, they are provided by Django's test suite:
+        field -- the field definition
+        created_separately -- True if the field was added via a SchemaEditor's AddField,
+                              False if the field was created with the model
+
+        Note that return value from this function is compared by tests against actual
+        introspection results; it should provide expectations, not run an introspection
+        itself.
+        """
+        if self.can_introspect_null and field and field.null:
+            return 'NullBooleanField'
+        return 'BooleanField'
+
 
 class BaseDatabaseOperations(object):
     """

django/db/backends/mysql/base.py

@@ -178,7 +178,6 @@ class DatabaseFeatures(BaseDatabaseFeatures):
     supports_regex_backreferencing = False
     supports_date_lookup_using_string = False
     can_introspect_binary_field = False
-    introspected_boolean_field_type = 'IntegerField'
     can_introspect_small_integer_field = True
     supports_timezones = False
     requires_explicit_null_ordering_when_grouping = True
@@ -225,6 +224,9 @@ class DatabaseFeatures(BaseDatabaseFeatures):
             cursor.execute("SELECT 1 FROM mysql.time_zone LIMIT 1")
             return cursor.fetchone() is not None
 
+    def introspected_boolean_field_type(self, *args):
+        return 'IntegerField'
+
 
 class DatabaseOperations(BaseDatabaseOperations):
     compiler_module = "django.db.backends.mysql.compiler"

django/db/backends/oracle/base.py

@@ -125,19 +125,20 @@ class DatabaseFeatures(BaseDatabaseFeatures):
     # select for update with limit can be achieved on Oracle, but not with the current backend.
     supports_select_for_update_with_limit = False
 
-    @cached_property
+    def introspected_boolean_field_type(self, field=None, created_separately=False):
-    def introspected_boolean_field_type(self):
         """
         Some versions of Oracle -- we've seen this on 11.2.0.1 and suspect
         it goes back -- have a weird bug where, when an integer column is
-        defined with a default, its precision is later reported on introspection
+        added to an existing table with a default, its precision is later
-        as 0, regardless of the real precision. For Django introspection, this
+        reported on introspection as 0, regardless of the real precision.
-        means that such columns are reported as IntegerField even if they are
+        For Django introspection, this means that such columns are reported
-        really BigIntegerField or BooleanField.
+        as IntegerField even if they are really BigIntegerField or BooleanField.
 
         The bug is solved in Oracle 11.2.0.2 and up.
         """
-        return 'IntegerField' if self.connection.oracle_full_version < '11.2.0.2' else 'BooleanField'
+        if self.connection.oracle_full_version < '11.2.0.2' and field and field.has_default() and created_separately:
+            return 'IntegerField'
+        return super(DatabaseFeatures, self).introspected_boolean_field_type(field, created_separately)
 
 
 class DatabaseOperations(BaseDatabaseOperations):

tests/inspectdb/tests.py

@@ -9,6 +9,8 @@ from django.db import connection
 from django.test import TestCase, skipUnlessDBFeature
 from django.utils.six import PY3, StringIO
 
+from .models import ColumnTypes
+
 
 class InspectDBTestCase(TestCase):
 
@@ -87,19 +89,18 @@ class InspectDBTestCase(TestCase):
         else:
             assertFieldType('big_int_field', "models.IntegerField()")
 
-        if connection.features.introspected_boolean_field_type == 'BooleanField':
+        bool_field = ColumnTypes._meta.get_field('bool_field')
-            assertFieldType('bool_field', "models.BooleanField()")
+        bool_field_type = connection.features.introspected_boolean_field_type(bool_field)
+        assertFieldType('bool_field', "models.{}()".format(bool_field_type))
+        null_bool_field = ColumnTypes._meta.get_field('null_bool_field')
+        null_bool_field_type = connection.features.introspected_boolean_field_type(null_bool_field)
+        if 'BooleanField' in null_bool_field_type:
+            assertFieldType('null_bool_field', "models.{}()".format(null_bool_field_type))
+        else:
             if connection.features.can_introspect_null:
-                assertFieldType('null_bool_field', "models.NullBooleanField()")
+                assertFieldType('null_bool_field', "models.{}(blank=True, null=True)".format(null_bool_field_type))
             else:
-                assertFieldType('null_bool_field', "models.BooleanField()")
+                assertFieldType('null_bool_field', "models.{}()".format(null_bool_field_type))
-        else:
-            field_type = connection.features.introspected_boolean_field_type
-            assertFieldType('bool_field', "models.{}()".format(field_type))
-            if connection.features.can_introspect_null:
-                assertFieldType('null_bool_field', "models.{}(blank=True, null=True)".format(field_type))
-            else:
-                assertFieldType('null_bool_field', "models.{}()".format(field_type))
 
         if connection.features.can_introspect_decimal_field:
             assertFieldType('decimal_field', "models.DecimalField(max_digits=6, decimal_places=1)")

tests/schema/tests.py

@@ -314,7 +314,7 @@ class SchemaTests(TransactionTestCase):
         columns = self.column_classes(Author)
         # BooleanField are stored as TINYINT(1) on MySQL.
         field_type = columns['awesome'][0]
-        self.assertEqual(field_type, connection.features.introspected_boolean_field_type)
+        self.assertEqual(field_type, connection.features.introspected_boolean_field_type(new_field, created_separately=True))
 
     def test_add_field_default_transform(self):
         """