name 'Serial' is not defined about piccolo

[dantownsend]

I came across this bug today - you're right, it's caused when creating a migration with a ForeignKey which uses LazyTableReference.

[hoosnick]

Serial is not added to extra_imports when rendering the template. Or is it related to --auto?

[dantownsend]

Ah, interesting - is this on the most recent version of Piccolo?

I wonder under what situations it happens? Were you adding a foreign key to an existing table, or was this a new table?

[hoosnick]

I had this problem with one previous version of Piccolo, and now I'm on the latest version.

When I added a foreign key to my forwarded(migrated) User and Tariff tables for Order table.

piccolo migrations new all --auto

...
...
...
✅ Finished

It worked for all apps without problems. But when I use the forwards command to migrate:

piccolo migrations forwards all

                          SESSION_AUTH

----------------------------------------------------------------
👍 2 migrations already complete
🏁 No migrations need to be run

                              USER

----------------------------------------------------------------
👍 4 migrations already complete
🏁 No migrations need to be run

                             COURSE

----------------------------------------------------------------
👍 1 migration already complete
⏩ 1 migration not yet run
🚀 Running 1 migration:
  - 2023-07-14T19:26:53:114807 [forwards]... ok! ✔️

                             USERS

----------------------------------------------------------------
👍 1 migration already complete
⏩ 1 migration not yet run
🚀 Running 1 migration:
  - 2023-07-14T19:26:53:440473 [forwards]... ok! ✔️

                            MY_APP

----------------------------------------------------------------
The command failed.
name 'Serial' is not defined
For a full stack trace, use --trace

[dantownsend]

Yeah, I think I saw this on a previous version of Piccolo. The fix is to manually add the import to the migration file:

from piccolo.columns.column_types import Serial

I need to try and figure out if it's a still a problem (i.e. if you create a new migration does it have this problem, or is it just for migrations created in older versions).

So far I've tried adding a foreign key to an existing table, and that included the Serial import.

[hoosnick]

The fix is to manually add the import to the migration file

Yes, I was doing this solution until now. But I thought this issue was a bug because it appeared in my 2-3 projects where different versions of Piccolo were used.

So far I've tried adding a foreign key to an existing table, and that included the Serial import.

So, do I need to migrate my foreign tables first and then add the foreign key? So sorted apps now can't be a help/solution either?

[hoosnick]

I had an empty db and empty piccolo_migrations folder (per app) in this try.

piccolo migrations new all --auto

piccolo migrations forwards all

[hoosnick]

@dantownsend The problem is with LazyTableReference and was solved when I removed it and imported the model from my other app/tables.py in the tables.py file.

[dantownsend]

@hoosnick Ah, that's good to know.

I was trying to find the commit where I thought I'd fixed the Serial import. This sounds like a new bug then with LazyTableReference.

[hoosnick]

@dantownsend Has the bug been fixed?

[dantownsend]

@hoosnick Not yet - I've had a look into it, but haven't created a PR yet.