Set updated/modified field as nullable

migrations/env.py

@@ -64,7 +64,7 @@ def run_migrations_online():
 
     with connectable.connect() as connection:
         context.configure(
-            connection=connection, target_metadata=target_metadata,
+            connection=connection, target_metadata=target_metadata
         )
 
         with context.begin_transaction():

migrations/versions/970563653ece_set_modified_updated_as_nullable.py

@@ -0,0 +1,45 @@
+"""set modified/updated as nullable
+
+Revision ID: 970563653ece
+Revises: 
+Create Date: 2020-07-22 23:40:07.674252
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = "970563653ece"
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    tables = {
+        "cities": "updated",
+        "games": "updated",
+        "games": "cancel_date",
+        "payments": "updated",
+        "player_availabilities": "updated",
+        "player_cancel_games": "updated",
+        "purchase_games": "updated",
+        "sports": "updated",
+        "teams": "updated",
+        "user_ratings": "updated",
+        "venues": "updated",
+        "venue_images": "updated",
+        "web_bookings": "updated",
+    }
+    for table, field in tables.items():
+        with op.batch_alter_table(table) as batch_op:
+            batch_op.alter_column(column_name=field, nullable=True, server_default=None)
+        query = "UPDATE {0} SET {1} = NULL WHERE {1} = '0000-00-00 00:00:00'".format(
+            table, field
+        )
+        op.execute(query)
+
+
+def downgrade():
+    pass

migrations/versions/eaa992d1469b_make_updated_field_nullable.py

@@ -1,45 +0,0 @@
-"""make updated field nullable
-
-Revision ID: eaa992d1469b
-Revises: 
-Create Date: 2020-07-04 18:08:31.035209
-
-"""
-from alembic import op
-import sqlalchemy as sa
-
-
-# revision identifiers, used by Alembic.
-revision = "eaa992d1469b"
-down_revision = None
-branch_labels = None
-depends_on = None
-
-
-def upgrade():
-    tables = {
-        "modified": "cities",
-        "modified": "games",
-        "cancel_date": "games",
-        "modified": "payments",
-        "modified": "player_availabilities",
-        "modified": "player_cancel_games",
-        "modified": "purchase_games",
-        "modified": "sports",
-        "modified": "teams",
-        "modified": "user_ratings",
-        "modified": "venues",
-        "updated": "venue_images",
-        "updated": "web_bookings",
-    }
-    for field, table in tables.items():
-        with op.batch_alter_table(table) as batch_op:
-            batch_op.alter_column(column_name=field, nullable=True)
-        query = "UPDATE {0} SET {1} = NULL WHERE {1} = '0000-00-00 00:00:00'".format(
-            table, field
-        )
-        op.execute(query)
-
-
-def downgrade():
-    pass

shell.nix

@@ -17,7 +17,6 @@ mkShell {
     python38Packages.twilio
     sqlite
     # Development tools
-    black
     python38Packages.isort
     python38Packages.pyflakes
   ];