Ticket #54: alter_column_null.diff

tests/logic.py

@@ -117 +117 @@
         app = self.create_test_app()
         
         self.assertEqual(
-            ["0001_spam", "0002_eggs"],
+            ["0001_spam", "0002_eggs", "0003_alter_spam"],
             migration.get_migration_names(app),
         )
     
@@ -129 +129 @@
         # Can't use vanilla import, modules beginning with numbers aren't in grammar
         M1 = __import__("fakeapp.migrations.0001_spam", {}, {}, ['Migration']).Migration
         M2 = __import__("fakeapp.migrations.0002_eggs", {}, {}, ['Migration']).Migration
+        M3 = __import__("fakeapp.migrations.0003_alter_spam", {}, {}, ['Migration']).Migration
         
         self.assertEqual(
-            [M1, M2],
+            [M1, M2, M3],
             list(migration.get_migration_classes(app)),
         )
     
@@ -158 +159 @@
             {app: {
                 "0001_spam": migration.get_migration(app, "0001_spam"),
                 "0002_eggs": migration.get_migration(app, "0002_eggs"),
+                "0003_alter_spam": migration.get_migration(app, "0003_alter_spam"),
             }},
             migration.all_migrations(),
         )
@@ -186 +188 @@
             (
                 (u"fakeapp", u"0001_spam"),
                 (u"fakeapp", u"0002_eggs"),
+                (u"fakeapp", u"0003_alter_spam"),
             ),
             migration.MigrationHistory.objects.values_list("app_name", "migration"),
         )
@@ -241 +244 @@
             (
                 (u"fakeapp", u"0001_spam"),
                 (u"fakeapp", u"0002_eggs"),
+                (u"fakeapp", u"0003_alter_spam"),
             ),
             migration.MigrationHistory.objects.values_list("app_name", "migration"),
         )
         
         # Now roll them backwards
+        migration.migrate_app(app, target_name="0002", resolve_mode=None, fake=False, silent=True)
         migration.migrate_app(app, target_name="0001", resolve_mode=None, fake=True, silent=True)
         migration.migrate_app(app, target_name="zero", resolve_mode=None, fake=False, silent=True)
         
         # Finish with none
         self.assertEqual(list(migration.MigrationHistory.objects.all()), [])
+    
+    def test_alter_column_null(self):
+        def null_ok(table_name, column_name):
+            from django.db import connection
+            cursor = connection.cursor()
+            for col in connection.introspection.get_table_description(cursor, table_name):
+                # elements as described in DB-API http://www.python.org/dev/peps/pep-0249/
+                if col[0] == column_name:
+                    return col[6]
+            raise Exception, 'column %s does not exist' % column_name        
+        
+        app = migration.get_app("fakeapp")
+        
+        # by default name is NOT NULL
+        migration.migrate_app(app, target_name="0002", resolve_mode=None, fake=False, silent=True)
+        self.failIf(null_ok("southtest_spam", 'name'))
+        
+        # after 0003, it should be NULL
+        migration.migrate_app(app, target_name="0003", resolve_mode=None, fake=False, silent=True)
+        self.assert_(null_ok("southtest_spam", 'name'))
+
+        # make sure it is NOT NULL again
+        migration.migrate_app(app, target_name="0002", resolve_mode=None, fake=False, silent=True)
+        self.failIf(null_ok("southtest_spam", 'name'), 'name not null after migration')
+        
+        # finish with no migrations, otherwise other tests fail...
+        migration.migrate_app(app, target_name="zero", resolve_mode=None, fake=False, silent=True)

db/generic.py

@@ -130 +130 @@
                 self.alter_column(table_name, name, field)
     
     alter_string_set_type = 'ALTER COLUMN %(column)s TYPE %(type)s'
-    alter_string_set_null = 'ALTER COLUMN %(column)s SET NOT NULL'
-    alter_string_drop_null = 'ALTER COLUMN %(column)s DROP NOT NULL'
+    alter_string_set_null = 'ALTER COLUMN %(column)s DROP NOT NULL'
+    alter_string_drop_null = 'ALTER COLUMN %(column)s SET NOT NULL'
     allows_combined_alters = True
     
     def alter_column(self, table_name, name, field):
@@ -173 +173 @@
             "type": field.db_type(),
         }
         if field.null:
+            sqls.append((self.alter_string_set_null % params, []))
+        else:
             sqls.append((self.alter_string_drop_null % params, []))
-        else:
-            sqls.append((self.alter_string_set_null % params, []))
         
         
         # TODO: Unique