#30526: migration to UUID id field doesn't properly convert integers (SQLite)
------------------------------+--------------------------------------
Reporter: Martin Baker | Owner: nobody
Type: Bug | Status: new
Component: Migrations | Version: 2.2
Severity: Normal | Resolution:
Keywords: UUID | Triage Stage: Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
------------------------------+--------------------------------------
Description changed by Martin Baker:
Old description:
> This may be present in other DBs, but I've noticed it with SQLite under
> Django 2.2.1.
>
> Steps to reproduce:
>
> 1. Start a model with an implicit integer id, and create and run the
> migration:
>
> {{{#!python
> from django.db import models
>
> class Something(models.Model):
> name = models.CharField(max_length=32)
> }}}
>
> 2. Then create one instance via the shell (`python manage.py shell`):
>
> {{{#!python
> from uuidbug.models import Something
> s = Something(name="One")
> s.save()
> }}}
>
> In the DB it looks like this (can use `python manage.py dbshell`):
> {{{
> sqlite> .headers on
> sqlite> select * from uuiditem_something;
> name|id
> One|1
> }}}
>
> 3. Edit the model to use UUIDs:
>
> {{{#!python
> import uuid
>
> from django.db import models
>
> class Something(models.Model):
> name = models.CharField(max_length=32)
> id = models.UUIDField(primary_key=True, default=uuid.uuid4,
> editable=False)
> }}}
>
> 4. After creating and running the migration, add another instance:
>
> {{{#!python
> from uuidbug.models import Something
> s = Something(name="After UUID-ization")
> s.save()
> }}}
>
> DB now looks like this:
>
> {{{
> sqlite> select * from uuiditem_something;
> name|id
> One|1
> After UUID-ization|693e1942d7d142289bb9fb3664f2c11a
> }}}
>
> Note that the id for the first instance has not been converted to a UUID
> properly. If you try to access the objects, you get an error:
>
> {{{#!python
> >>> Something.objects.all()
> Traceback (most recent call last):
> File "<console>", line 1, in <module>
> File "/Users/martin/Connery/opencc-backend/venv/lib/python3.7/site-
> packages/django/db/models/manager.py", line 82, in manager_method
> return getattr(self.get_queryset(), name)(*args, **kwargs)
> File "/Users/martin/Connery/opencc-backend/venv/lib/python3.7/site-
> packages/django/db/models/query.py", line 653, in first
> for obj in (self if self.ordered else self.order_by('pk'))[:1]:
> File "/Users/martin/Connery/opencc-backend/venv/lib/python3.7/site-
> packages/django/db/models/query.py", line 274, in __iter__
> self._fetch_all()
> File "/Users/martin/Connery/opencc-backend/venv/lib/python3.7/site-
> packages/django/db/models/query.py", line 1242, in _fetch_all
> self._result_cache = list(self._iterable_class(self))
> File "/Users/martin/Connery/opencc-backend/venv/lib/python3.7/site-
> packages/django/db/models/query.py", line 72, in __iter__
> for row in compiler.results_iter(results):
> File "/Users/martin/Connery/opencc-backend/venv/lib/python3.7/site-
> packages/django/db/models/sql/compiler.py", line 1044, in
> apply_converters
> value = converter(value, expression, connection)
> File "/Users/martin/Connery/opencc-backend/venv/lib/python3.7/site-
> packages/django/db/backends/sqlite3/operations.py", line 294, in
> convert_uuidfield_value
> value = uuid.UUID(value)
> File
> "/usr/local/Cellar/python/3.7.3/Frameworks/Python.framework/Versions/3.7/lib/python3.7/uuid.py",
> line 160, in __init__
> raise ValueError('badly formed hexadecimal UUID string')
> ValueError: badly formed hexadecimal UUID string
> }}}
New description:
This may be present in other DBs, but I've noticed it with SQLite under
Django 2.2.1.
Steps to reproduce:
1. Start a model with an implicit integer id, and create and run the
migration:
{{{#!python
from django.db import models
class Something(models.Model):
name = models.CharField(max_length=32)
}}}
2. Then create one instance via the shell (`python manage.py shell`):
{{{#!python
from uuidbug.models import Something
s = Something(name="One")
s.save()
}}}
In the DB it looks like this (can use `python manage.py dbshell`):
{{{
sqlite> .headers on
sqlite> select * from uuiditem_something;
name|id
One|1
}}}
3. Edit the model to use UUIDs:
{{{#!python
import uuid
from django.db import models
class Something(models.Model):
name = models.CharField(max_length=32)
id = models.UUIDField(primary_key=True, default=uuid.uuid4,
editable=False)
}}}
4. After creating and running the migration, add another instance:
{{{#!python
from uuidbug.models import Something
s = Something(name="After UUID-ization")
s.save()
}}}
DB now looks like this:
{{{
sqlite> select * from uuidbug_something;
name|id
One|1
After UUID-ization|693e1942d7d142289bb9fb3664f2c11a
}}}
Note that the id for the first instance has not been converted to a UUID
properly. If you try to access the objects, you get an error:
{{{#!python
>>> Something.objects.all()
Traceback (most recent call last):
File "<console>", line 1, in <module>
File "/Users/martin/Connery/opencc-backend/venv/lib/python3.7/site-
packages/django/db/models/manager.py", line 82, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/Users/martin/Connery/opencc-backend/venv/lib/python3.7/site-
packages/django/db/models/query.py", line 653, in first
for obj in (self if self.ordered else self.order_by('pk'))[:1]:
File "/Users/martin/Connery/opencc-backend/venv/lib/python3.7/site-
packages/django/db/models/query.py", line 274, in __iter__
self._fetch_all()
File "/Users/martin/Connery/opencc-backend/venv/lib/python3.7/site-
packages/django/db/models/query.py", line 1242, in _fetch_all
self._result_cache = list(self._iterable_class(self))
File "/Users/martin/Connery/opencc-backend/venv/lib/python3.7/site-
packages/django/db/models/query.py", line 72, in __iter__
for row in compiler.results_iter(results):
File "/Users/martin/Connery/opencc-backend/venv/lib/python3.7/site-
packages/django/db/models/sql/compiler.py", line 1044, in apply_converters
value = converter(value, expression, connection)
File "/Users/martin/Connery/opencc-backend/venv/lib/python3.7/site-
packages/django/db/backends/sqlite3/operations.py", line 294, in
convert_uuidfield_value
value = uuid.UUID(value)
File
"/usr/local/Cellar/python/3.7.3/Frameworks/Python.framework/Versions/3.7/lib/python3.7/uuid.py",
line 160, in __init__
raise ValueError('badly formed hexadecimal UUID string')
ValueError: badly formed hexadecimal UUID string
}}}
--
--
Ticket URL: <https://code.djangoproject.com/ticket/30526#comment:1>
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