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Improper UUID serialisation dropping leading zeros ▶️ "ValueError: badly formed hexadecimal UUID string" #25
Description
First Check
- I added a very descriptive title to this issue.
- I used the GitHub search to find a similar issue and didn't find it.
- I searched the SQLModel documentation, with the integrated search.
- I already searched in Google "How to X in SQLModel" and didn't find any information.
- I already read and followed all the tutorial in the docs and didn't find an answer.
- I already checked if it is not related to SQLModel but to Pydantic.
- I already checked if it is not related to SQLModel but to SQLAlchemy.
Commit to Help
- I commit to help with one of those options 👆
Example Code
import uuid
from typing import Optional
import sqlalchemy.exc
from sqlmodel import SQLModel, Field
from sqlmodel import create_engine, Session, select
class Hero(SQLModel, table=True):
id: Optional[uuid.UUID] = Field(primary_key=True,
default_factory=uuid.uuid4)
name: str
secret_name: str
age: Optional[int] = None
def __str__(self):
return f'{self.name} (AKA {self.secret_name}) [{self.age if self.age is not None else "Unknown"}]'
sqlite_file_name = "database.db"
sqlite_url = f"sqlite:///{sqlite_file_name}"
engine = create_engine(sqlite_url, echo=True) # remove echo for prod
def create_db_and_tables():
try:
Hero.__table__.drop(engine)
except sqlalchemy.exc.OperationalError: # table doesn't exist yet
pass
SQLModel.metadata.create_all(engine)
def create_heroes():
heros = [
Hero(name="Deadpond", secret_name="Dive Wilson"),
Hero(name="Spider-Boy", secret_name="Pedro Parqueador"),
Hero(name="Rusty-Man", secret_name="Tommy Sharp", age=48),
Hero(name="Tarantula", secret_name="Natalia Roman-on", age=32),
Hero(name="Black Lion", secret_name="Trevor Challa", age=35),
Hero(name="Dr. Weird", secret_name="Steve Weird", age=36),
Hero(name="Captain North America", secret_name="Esteban Rogelios", age=93),
]
with Session(engine) as session:
for hero in heros:
session.add(hero)
session.commit()
def select_heroes():
with Session(engine) as session:
for hero in session.exec(select(Hero)):
print(hero.id)
if __name__ == "__main__":
while True:
try:
create_db_and_tables()
create_heroes()
select_heroes()
except ValueError:
raiseCleansed Traceback
Traceback (most recent call last):
File “/…/sqlmodel_tutorial/minimal_example.py", line 89, in <module>
select_heroes()
File “/…/sqlmodel_tutorial/minimal_example.py", line 80, in select_heroes
for hero in session.exec(select(Hero)):
File "/.../lib/python3.8/site-packages/sqlalchemy/engine/result.py", line 381, in iterrows
for row in self._fetchiter_impl():
File "/.../lib/python3.8/site-packages/sqlalchemy/orm/loading.py", line 147, in chunks
fetch = cursor._raw_all_rows()
File "/.../lib/python3.8/site-packages/sqlalchemy/engine/result.py", line 392, in _raw_all_rows
return [make_row(row) for row in rows]
File "/.../lib/python3.8/site-packages/sqlalchemy/engine/result.py", line 392, in <listcomp>
return [make_row(row) for row in rows]
File "/.../lib/python3.8/site-packages/sqlalchemy/sql/type_api.py", line 1430, in process
return process_value(value, dialect)
File "/.../lib/python3.8/site-packages/sqlmodel/sql/sqltypes.py", line 61, in process_result_value
value = uuid.UUID(value)
File “/…/lib/python3.8/uuid.py", line 171, in __init__
raise ValueError('badly formed hexadecimal UUID string')
ValueError: badly formed hexadecimal UUID string
Description
Running through the tutorial up until around this point, I tried swapping out the int id key for a UUID key.
This works except whenever the uuid.uuid4 default factory creates a UUID with a hexstring that starts with a zero.
It appears that here in sqltypes.py that, rather than using UUID().hex, sqltypes.py carries on sqlalchemy's integer stringification apprach, however, doesn't include any padding declaration.
IMO there are two options;
- faithfully fix the replication of SQLAlchemy's UUID ▶️ int ▶️ str approach with the padding fixed (f"{v.int:032x}")
- switch to using the stdlib UUID.hex implementation for serialisation
Personally I'm a fan of the latter so will spin up a PR
Operating System
macOS
Operating System Details
No response
SQLModel Version
0.0.4
Python Version
3.8.8
Additional Context
No response
Activity
Update GUID handling use stdlib UUID.hex
alucarddelta commented on Sep 1, 2021
I am also hitting this issue with UUIDs being "badly formed".
dit7ya commented on Sep 27, 2021
I am also getting this issue. A new release with the PR merged will be very helpful.
Use a fork of SQLModel
Use a fork of SQLModel
chriswhite199 commented on Nov 29, 2021
For those awaiting a fix for this, here's a method to ensure the generated UUIDs don't start with leading zeros:
frankie567 commented on Nov 30, 2021
Other solution: installing the version of @andrewbolster's PR:
junekiwi commented on Dec 20, 2021
Another (temporary) solution, with SQLAlchemy-Utils:
Use my own fork of SQLModel 0.0.6 merged with andrewbolster's fork
mkarbo commented on Mar 16, 2022
@tiangolo is there any update on this?
fix: work around for fastapi/sqlmodel#25
Merge pull request fastapi#25 from leynier/fork-3
tiangolo commented on Aug 27, 2022
Thanks for the report and fix in #26 @andrewbolster! 🍰
And thanks everyone for the discussion. ☕
The fix will be available in SQLModel 0.0.7, released in the next hours. 🎉
Increase sqlmodel version to ^0.0.7