Opened 5 years ago
Closed 5 years ago
#31199 closed Bug (duplicate)
CheckConstraints with F objects don't apply on SQLite
Reported by: | Adam Johnson | Owned by: | nobody |
---|---|---|---|
Component: | Database layer (models, ORM) | Version: | dev |
Severity: | Normal | Keywords: | |
Cc: | Simon Charette | Triage Stage: | Unreviewed |
Has patch: | no | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | no |
Easy pickings: | no | UI/UX: | no |
Description
Take this model with CheckConstraint:
class Book(models.Model): percent_read = models.PositiveIntegerField() percent_unread = models.PositiveIntegerField() percent_ignored = models.PositiveIntegerField() def __str__(self): return f"{self.id} - {self.percent_read}% read" class Meta: constraints = [ models.CheckConstraint( check=models.Q( percent_read=( 100 - models.F("percent_unread") - models.F("percent_ignored") ) ), name="percentages_sum_100", ) ]
Applying the migration to create the constraint works on MariaDB but fails on SQLite.
The sqlmigrate
output on SQLite shows the F objects get resolved to the full table name, which is what breaks during renaming phase in the migration:
$ python manage.py sqlmigrate core 0002 BEGIN; -- -- Create constraint percentages_sum_100 on model book -- CREATE TABLE "new__core_book" ("id" integer NOT NULL PRIMARY KEY AUTOINCREMENT, "percent_read" integer unsigned NOT NULL CHECK ("percent_read" >= 0), "percent_unread" integer unsigned NOT NULL CHECK ("percent_unread" >= 0), "percent_ignored" integer unsigned NOT NULL CHECK ("percent_ignored" >= 0), CONSTRAINT "percentages_sum_100" CHECK ("percent_read" = ((100 - "new__core_book"."percent_unread") - "new__core_book"."percent_ignored"))); INSERT INTO "new__core_book" ("id", "percent_read", "percent_unread", "percent_ignored") SELECT "id", "percent_read", "percent_unread", "percent_ignored" FROM "core_book"; DROP TABLE "core_book"; ALTER TABLE "new__core_book" RENAME TO "core_book"; COMMIT; $ python manage.py migrate ... django.db.utils.DatabaseError: malformed database schema (core_book) - no such column: new__core_book.percent_unread
Full repo for reproduction: https://github.com/adamchainz/django-issue-check-constraint-reference
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Duplicate of #31197, apologies I got a couple 504's from Nginx so resubmitted.