CODEWITHSUNDEEP
pythondjangodjango-modelsdjango-orm
Prometheus
Prometheus

Reputation: 33615

Django migration error can't adapt type UUID

I've changed my model PK from this:

id = models.CharField(primary_key=True, unique=True, default=make_key, max_length=32)

to this

id = models.UUIDField(primary_key=True, unique=True, default=TimeUUID, editable=False)

Where TimeUUID is this function. However, I get an error when running migrate below, why?

The DB has no data in I cleared all rows. The function generates UUIDs that look like this:

00332873-d693-da82-720e-27dff1cf2a9b
00332873-d693-db36-dd92-eac7c082f13c
00332873-d693-dc0a-aef8-9fb752a3fb6c

i.e. [32 bits timestamp high]-[16 bits timestamp mid]-[16 bits timestamp low]-[16 bits random]-[48 bits random]

The DB is Postgres.

Error:

  File "/Users/user/Documents/app/env/lib/python3.4/site-packages/django/db/backends/utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
django.db.utils.ProgrammingError: can't adapt type 'TimeUUID'

Could it be that the Django UUID field does not accept UUIDs with bits in a different order?

Also tried:

def get_UUID():
    return TimeUUID()

Then 

id = models.UUIDField(primary_key=True, unique=True, default=get_UUID, editable=False)

Which still gives the same error.

Upvotes: 0

Views: 948

Answers (1)

Daniel Roseman
Daniel Roseman

Reputation: 599580

TimeUUID is a class. Calling it returns an instance of that class. Django has no idea what to do with that value, as there is no clue how it could be stored as a value in the database.

In order to use it, you'd need to convert it to a string. You could do that in a lambda:

id = models.UUIDField(
    primary_key=True, unique=True, default=lambda: str(TimeUUID()), editable=False)

Upvotes: 1

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