Fixed #22001 -- Ensure db_type is respected.

db_parameters should respect an already existing db_type method and
return that as its type string. In particular, this was causing some
fields from gis to not be generated.

Thanks to @bigsassy and @blueyed for their work on the patch.

Also fixed #22260

AUTHORS

@@ -147,6 +147,7 @@ answer newbie questions, and generally made Django that much better:
     Ricardo Javier Cárdenes Medina <ricardo.cardenes@gmail.com>
     Jeremy Carbaugh <jcarbaugh@gmail.com>
     Graham Carlyle <graham.carlyle@maplecroft.net>
+    Eric Palakovich Carr <carreric@gmail.com>
     Juan Catalano <catalanojuan@gmail.com>
     Antonio Cavedoni <http://cavedoni.com/>
     cedric@terramater.net

django/contrib/gis/tests/migrations/migrations/0001_initial.py

@@ -0,0 +1,33 @@
+from django.db import models, migrations
+import django.contrib.gis.db.models.fields
+
+
+# Used for regression test of ticket #22001: https://code.djangoproject.com/ticket/22001
+class Migration(migrations.Migration):
+
+    operations = [
+        migrations.CreateModel(
+            name='Neighborhood',
+            fields=[
+                (u'id', models.AutoField(verbose_name=u'ID', serialize=False, auto_created=True, primary_key=True)),
+                ('name', models.TextField(unique=True)),
+                ('geom', django.contrib.gis.db.models.fields.MultiPolygonField(srid=4326, null=True)),
+            ],
+            options={
+            },
+            bases=(models.Model,),
+        ),
+        migrations.CreateModel(
+            name='Household',
+            fields=[
+                (u'id', models.AutoField(verbose_name=u'ID', serialize=False, auto_created=True, primary_key=True)),
+                ('neighborhood', models.ForeignKey(to='gis.Neighborhood', to_field=u'id', null=True)),
+                ('address', models.TextField()),
+                ('zip_code', models.IntegerField(null=True, blank=True)),
+                ('geom', django.contrib.gis.db.models.fields.PointField(srid=4326, null=True, geography=True)),
+            ],
+            options={
+            },
+            bases=(models.Model,),
+        )
+    ]

django/contrib/gis/tests/migrations/test_commands.py

@@ -0,0 +1,47 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.core.management import call_command
+from django.db import connection
+from django.test import override_settings, override_system_checks, TransactionTestCase
+
+
+class MigrateTests(TransactionTestCase):
+    """
+    Tests running the migrate command in Geodjango.
+    """
+    available_apps = ["django.contrib.gis"]
+
+    def get_table_description(self, table):
+        with connection.cursor() as cursor:
+            return connection.introspection.get_table_description(cursor, table)
+
+    def assertTableExists(self, table):
+        with connection.cursor() as cursor:
+            self.assertIn(table, connection.introspection.get_table_list(cursor))
+
+    def assertTableNotExists(self, table):
+        with connection.cursor() as cursor:
+            self.assertNotIn(table, connection.introspection.get_table_list(cursor))
+
+    @override_system_checks([])
+    @override_settings(MIGRATION_MODULES={"gis": "django.contrib.gis.tests.migrations.migrations"})
+    def test_migrate_gis(self):
+        """
+        Tests basic usage of the migrate command when a model uses Geodjango
+        fields. Regression test for ticket #22001:
+        https://code.djangoproject.com/ticket/22001
+        """
+        # Make sure no tables are created
+        self.assertTableNotExists("migrations_neighborhood")
+        self.assertTableNotExists("migrations_household")
+        # Run the migrations to 0001 only
+        call_command("migrate", "gis", "0001", verbosity=0)
+        # Make sure the right tables exist
+        self.assertTableExists("gis_neighborhood")
+        self.assertTableExists("gis_household")
+        # Unmigrate everything
+        call_command("migrate", "gis", "zero", verbosity=0)
+        # Make sure it's all gone
+        self.assertTableNotExists("gis_neighborhood")
+        self.assertTableNotExists("gis_household")

django/db/models/fields/__init__.py

@@ -511,7 +511,7 @@ class Field(RegisterLookupMixin):
         connection.
         """
         # The default implementation of this method looks at the
-        # backend-specific DATA_TYPES dictionary, looking up the field by its
+        # backend-specific data_types dictionary, looking up the field by its
         # "internal type".
         #
         # A Field class can implement the get_internal_type() method to specify
@@ -525,24 +525,20 @@ class Field(RegisterLookupMixin):
         # mapped to one of the built-in Django field types. In this case, you
         # can implement db_type() instead of get_internal_type() to specify
         # exactly which wacky database column type you want to use.
-        params = self.db_parameters(connection)
-        if params['type']:
-            if params['check']:
-                return "%s CHECK (%s)" % (params['type'], params['check'])
-            else:
-                return params['type']
+        data = DictWrapper(self.__dict__, connection.ops.quote_name, "qn_")
+        try:
+            return connection.creation.data_types[self.get_internal_type()] % data
+        except KeyError:
             return None
 
     def db_parameters(self, connection):
         """
-        Replacement for db_type, providing a range of different return
-        values (type, checks)
+        Extension of db_type(), providing a range of different return
+        values (type, checks).
+        This will look at db_type(), allowing custom model fields to override it.
         """
         data = DictWrapper(self.__dict__, connection.ops.quote_name, "qn_")
-        try:
-            type_string = connection.creation.data_types[self.get_internal_type()] % data
-        except KeyError:
-            type_string = None
+        type_string = self.db_type(connection)
         try:
             check_string = connection.creation.data_type_check_constraints[self.get_internal_type()] % data
         except KeyError:

tests/field_subclassing/fields.py

@@ -74,3 +74,8 @@ class JSONField(six.with_metaclass(models.SubfieldBase, models.TextField)):
         if value is None:
             return None
         return json.dumps(value)
+
+
+class CustomTypedField(models.TextField):
+    def db_type(self, connection):
+        return 'custom_field'

tests/field_subclassing/tests.py

@@ -3,9 +3,10 @@ from __future__ import unicode_literals
 import inspect
 
 from django.core import serializers
+from django.db import connection
 from django.test import TestCase
 
-from .fields import Small
+from .fields import Small, CustomTypedField
 from .models import DataModel, MyModel, OtherModel
 
 
@@ -104,3 +105,10 @@ class CustomField(TestCase):
         data = dict(inspect.getmembers(MyModel))
         self.assertIn('__module__', data)
         self.assertEqual(data['__module__'], 'field_subclassing.models')
+
+
+class TestDbType(TestCase):
+
+    def test_db_parameters_respects_db_type(self):
+        f = CustomTypedField()
+        self.assertEqual(f.db_parameters(connection)['type'], 'custom_field')