#28297: Same queryset result in two different queries on ORM
-------------------------------------+-------------------------------------
Reporter: Marcus Renno | Owner: Tom
Type: Bug | Status: assigned
Component: Database layer | Version: 1.11
(models, ORM) |
Severity: Normal | Resolution:
Keywords: join, annotation, F | Triage Stage:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
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Comment (by Marcus Renno):
That seems to be right, Tom. `join()` is relying on the order of the
dictionary order resulting from `.items()`.
It's weird that setting the hash seed to 2 would solve this problem,
though. I feel like the framework should not rely on the user changing the
hashing seed to a static number to fix this problem, because it breaks the
purpose (security) of the the hashing being random.
Replying to [comment:11 Tom]:
> It seems to boil down to this line:
https://github.com/django/django/blob/stable/1.11.x/django/db/models/sql/query.py#L927
>
> The `alias_map.items()` isn't stable, with `PYTHONHASHSEED=1` then
`reuse[0]` is `recepie_steps`, which is incorrect, but with it set to `2`
then `reuse[0]` is (correctly) `T6`.
>
> If anyone knows how to fix this then please let me know, else I will try
and find a suitable fix.
--
Ticket URL: <https://code.djangoproject.com/ticket/28297#comment:12>
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