`Migration is unrecognised` if already ran migration id is specified and there are any not launched after it

[metakot]

TL,DR:

piccolo migrations forwards foo.bar migration1
ok
piccolo migrations forwards foo.bar migration2
ok
piccolo migrations backwards foo.bar
ok
piccolo migrations forwards foo.bar migration1
migration1 is unrecognised

should be 🏁 No migrations need to be run

So I have quite a few apps and migrations that have become dependent on each other, and to make them work correctly I use this script:

#!/bin/bash
set -e
piccolo migrations forwards session_auth
piccolo migrations forwards user
piccolo migrations forwards apps.employee
piccolo migrations forwards apps.car
piccolo migrations forwards apps.price 2024-05-21T06:27:34:451504   # <-- breaks here
piccolo migrations forwards apps.rent
piccolo migrations forwards apps.price   # again because of subsequent dependent migrations
piccolo migrations forwards all  # everything else
python main.py

the specified migration in app "apps.price" is needed by subsequent migrations in dependent apps (apps.rent).
Everything was working fine until I decided to add new migration to the apps.price.

The structure of migrations directory is:

appsprice_2024_05_21t06_27_34_451504.py  # created back when piccolo was 1.5.0
appsprice_2024_05_21t06_31_03_491490.py  # created back when piccolo was 1.5.0
appsprice_2024_05_21t06_54_59_701243.py  # created back when piccolo was 1.5.0
appsprice_2026_02_24t22_16_29_046939.py  # fresh piccolo version
appsprice_2026_02_24t22_20_02_371610.py  # fresh piccolo version

What is happening in

piccolo/piccolo/apps/migrations/commands/forwards.py

Line 63 in c9d27e6

message = f"{self.migration_id} is unrecognised"

print(ids)
['2024-05-21T06:27:34:451504', '2024-05-21T06:31:03:491490', '2024-05-21T06:54:59:701243', '2026-02-24T22:16:29:046939', '2026-02-24T22:20:02:371610']
print(already_ran)
['2024-05-21T06:27:34:451504', '2024-05-21T06:31:03:491490', '2024-05-21T06:54:59:701243']
print(havent_run)
['2026-02-24T22:16:29:046939', '2026-02-24T22:20:02:371610']

And of course the mentioned 2024-05-21T06:27:34:451504 is absent in havent_run because it is already ran and piccolo shows 2024-05-21T06:27:34:451504 is unrecognised.

What I propose:

piccolo/piccolo/apps/migrations/commands/forwards.py

Line 45 in c9d27e6

if len(havent_run) == 0:

change this line to

if len(havent_run) == 0 or self.migration_id in already_ran:  # or reuse set(already_ran)

so then piccolo successfully prints 🏁 No migrations need to be run

[dantownsend]

So the problem here is there's no way to run a migration which has already ran? And the message Piccolo prints out is misleading because it makes it sound like the migration doesn't exist.

It's something we might be able to do - if someone wants to run a migration, we could say 'it has already run, are you sure want to re-run it?'. And the user can enter yes.

[metakot]

It not only prints a message, but also returns an error status, causing the automated script to break. Sooo yes, Piccolo can just exit with status 0 in quiet mode, for example.