replace % with mod() SQL function to avoid invalid double-percentage …

[AngryUbuntuNerd]

fixes #922

invalid SQL before:

SELECT
	`django_celery_beat_periodictask`.`id`,
	`django_celery_beat_periodictask`.`name`,
	`django_celery_beat_periodictask`.`task`,
	`django_celery_beat_periodictask`.`interval_id`,
	`django_celery_beat_periodictask`.`crontab_id`,
	`django_celery_beat_periodictask`.`solar_id`,
	`django_celery_beat_periodictask`.`clocked_id`,
	`django_celery_beat_periodictask`.`args`,
	`django_celery_beat_periodictask`.`kwargs`,
	`django_celery_beat_periodictask`.`queue`,
	`django_celery_beat_periodictask`.`exchange`,
	`django_celery_beat_periodictask`.`routing_key`,
	`django_celery_beat_periodictask`.`headers`,
	`django_celery_beat_periodictask`.`priority`,
	`django_celery_beat_periodictask`.`expires`,
	`django_celery_beat_periodictask`.`expire_seconds`,
	`django_celery_beat_periodictask`.`one_off`,
	`django_celery_beat_periodictask`.`start_time`,
	`django_celery_beat_periodictask`.`enabled`,
	`django_celery_beat_periodictask`.`last_run_at`,
	`django_celery_beat_periodictask`.`total_run_count`,
	`django_celery_beat_periodictask`.`date_changed`,
	`django_celery_beat_periodictask`.`description`
FROM
	`django_celery_beat_periodictask`
LEFT OUTER JOIN `django_celery_beat_clockedschedule` ON
	(`django_celery_beat_periodictask`.`clocked_id` = `django_celery_beat_clockedschedule`.`id`)
WHERE
	(`django_celery_beat_periodictask`.`enabled` = 1
		AND NOT (((`django_celery_beat_clockedschedule`.`clocked_time` > '2025-07-29 14:05:32.092804'
			AND `django_celery_beat_clockedschedule`.`clocked_time` IS NOT NULL
			AND `django_celery_beat_periodictask`.`clocked_id` IS NOT NULL)
		OR (`django_celery_beat_periodictask`.`crontab_id` IS NOT NULL
			AND `django_celery_beat_periodictask`.`crontab_id` IN (
			SELECT
				U0.`id` AS `id`
			FROM
				`django_celery_beat_crontabschedule` U0
			WHERE
				(U0.`hour` REGEXP BINARY '^\\d+$'
					AND NOT (CASE
						WHEN (U0.`timezone` = 'UTC') THEN (((CAST(U0.`hour` AS signed integer) + 0) + 24) %% 24)
						ELSE CAST(U0.`hour` AS signed integer)
					END IN (12, 13, 14, 15, 16, 4))))
				AND `django_celery_beat_periodictask`.`crontab_id` IS NOT NULL))))

new SQL:

SELECT
	`django_celery_beat_periodictask`.`id`,
	`django_celery_beat_periodictask`.`name`,
	`django_celery_beat_periodictask`.`task`,
	`django_celery_beat_periodictask`.`interval_id`,
	`django_celery_beat_periodictask`.`crontab_id`,
	`django_celery_beat_periodictask`.`solar_id`,
	`django_celery_beat_periodictask`.`clocked_id`,
	`django_celery_beat_periodictask`.`args`,
	`django_celery_beat_periodictask`.`kwargs`,
	`django_celery_beat_periodictask`.`queue`,
	`django_celery_beat_periodictask`.`exchange`,
	`django_celery_beat_periodictask`.`routing_key`,
	`django_celery_beat_periodictask`.`headers`,
	`django_celery_beat_periodictask`.`priority`,
	`django_celery_beat_periodictask`.`expires`,
	`django_celery_beat_periodictask`.`expire_seconds`,
	`django_celery_beat_periodictask`.`one_off`,
	`django_celery_beat_periodictask`.`start_time`,
	`django_celery_beat_periodictask`.`enabled`,
	`django_celery_beat_periodictask`.`last_run_at`,
	`django_celery_beat_periodictask`.`total_run_count`,
	`django_celery_beat_periodictask`.`date_changed`,
	`django_celery_beat_periodictask`.`description`
FROM
	`django_celery_beat_periodictask`
LEFT OUTER JOIN `django_celery_beat_clockedschedule` ON
	(`django_celery_beat_periodictask`.`clocked_id` = `django_celery_beat_clockedschedule`.`id`)
WHERE
	(`django_celery_beat_periodictask`.`enabled` = 1
		AND NOT (((`django_celery_beat_clockedschedule`.`clocked_time` > '2025-07-29 10:42:42.813538'
			AND `django_celery_beat_clockedschedule`.`clocked_time` IS NOT NULL
			AND `django_celery_beat_periodictask`.`clocked_id` IS NOT NULL)
		OR (`django_celery_beat_periodictask`.`crontab_id` IS NOT NULL
			AND `django_celery_beat_periodictask`.`crontab_id` IN (
			SELECT
				U0.`id` AS `id`
			FROM
				`django_celery_beat_crontabschedule` U0
			WHERE
				(U0.`hour` REGEXP BINARY '^\\d+$'
					AND NOT (CASE
						WHEN (U0.`timezone` = 'UTC') THEN MOD(((CAST(U0.`hour` AS signed integer) + 0) + 24), 24)
						ELSE CAST(U0.`hour` AS signed integer)
					END IN (12, 13, 14, 15, 16, 4))))
				AND `django_celery_beat_periodictask`.`crontab_id` IS NOT NULL))))

[Copilot]

Pull Request Overview

This PR fixes a SQL generation issue where Django was producing invalid double-percentage (%%) operators in MySQL queries. The fix replaces the Python modulo operator (%) with Django's Func class using the SQL MOD() function to ensure proper SQL syntax.

Key Changes

• Replaces Python modulo operator with Django's Func class using MOD function
• Wraps the expression in ExpressionWrapper with proper output field type
• Adds necessary imports for ExpressionWrapper and Func

[Copilot]

[nitpick] The import statement is split across multiple lines in an inconsistent format. Consider keeping all imports on the same line or using a more consistent multi-line format with proper indentation.

Suggested change

	from django.db.models import (Case, ExpressionWrapper, F, Func, IntegerField,
	Q, When)
	from django.db.models import (
	Case, ExpressionWrapper, F, Func, IntegerField, Q, When
	)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.19%. Comparing base (f1f239c) to head (19e59c3).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #923   +/-   ##
=======================================
  Coverage   88.19%   88.19%           
=======================================
  Files          32       32           
  Lines        1008     1008           
  Branches      105      105           
=======================================
  Hits          889      889           
  Misses        101      101           
  Partials       18       18           

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[auvipy]

is nit pissible to modify the relevant tests as well?

[AngryUbuntuNerd]

can you give me some guidance there:

1. which test needs modifying?
2. how do I run the tests locally? the README does not seem to say

[auvipy]

this should be the primary file https://github.com/celery/django-celery-beat/blob/main/t/unit/test_schedulers.py

and for tests there are docker and tox for running tests locally