Opened 3 hours ago
Last modified 3 hours ago
#36085 assigned Bug
SQLite backend raises exception on negative array indices in JSONField
| Reported by: | savanto | Owned by: | savanto |
|---|---|---|---|
| Component: | Database layer (models, ORM) | Version: | 5.1 |
| Severity: | Normal | Keywords: | sqlite, jsonfield |
| Cc: | Triage Stage: | Unreviewed | |
| Has patch: | yes | Needs documentation: | no |
| Needs tests: | no | Patch needs improvement: | no |
| Easy pickings: | no | UI/UX: | no |
Description
Positive jsonfield array index queries can be constructed the usual way with kwargs (ie. Model.objects.filter(jsonfield__2=1)), while negative jsonfield array index query must be constructed using the splat operator on a dict: Model.objects.filter(**{"jsonfield__-2": 1})). When querying jsonfields in this way on the SQLite backend, the following error arises:
django.db.utils.OperationalError: bad JSON path: '$[-2]'
When constructing the query, the JSON path constructor simply appends any numerical value to the path (https://github.com/django/django/blob/5.1.4/django/db/models/fields/json.py#L155). But the SQLite backend uses a special syntax for performing negative-indexing in jsonfields (https://sqlite.org/json1.html#path_arguments) that is different from other backends: negative indices must be prepended by a literal # character.
https://github.com/django/django/pull/19030