ArgumentError using Mixin classes

[filipposantovito]

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Example Code

from datetime import datetime
from typing import Optional

from pydantic import BaseModel
from sqlmodel import SQLModel, Column, DateTime, Field, Session, create_engine

# it doesnt matter if base class is BaseModel, SQLModel or object
class TimeStampMixin(BaseModel):
    created_at: Optional[datetime] = Field(
        sa_column=Column(
            DateTime,
            default=datetime.utcnow,
            nullable=False,
        )
    )

    updated_at: Optional[datetime] = Field(
        sa_column=Column(
            DateTime,
            default=datetime.utcnow,
            onupdate=datetime.utcnow,
        )
    )


class MyModel(SQLModel, TimeStampMixin, table=True):
    id: Optional[int] = Field(default=None, primary_key=True)
    name: str


class MyModel2(SQLModel, TimeStampMixin, table=True):
    id: Optional[int] = Field(default=None, primary_key=True)
    name: str

engine = create_engine("sqlite:///database.db")
SQLModel.metadata.create_all(engine)

with Session(bind=engine) as session:
    session.add(MyModel(name="A Name"))
    session.commit()

Description

the code above throws an exception while it is supposed to work. This is the stacktrace:

(venv) filippo@dev101:~/tmp/sqlmodel_mixin$ python main.py
Traceback (most recent call last):
File "/home/filippo/tmp/sqlmodel_mixin/main.py", line 32, in
class MyModel2( TimeStampMixin, table=True):
File "/home/filippo/tmp/sqlmodel_mixin/venv/lib/python3.10/site-packages/sqlmodel/main.py", line 641, in init
DeclarativeMeta.init(cls, classname, bases, dict_, **kw)
File "/home/filippo/tmp/sqlmodel_mixin/venv/lib/python3.10/site-packages/sqlalchemy/orm/decl_api.py", line 198, in init
as_declarative(reg, cls, dict)
File "/home/filippo/tmp/sqlmodel_mixin/venv/lib/python3.10/site-packages/sqlalchemy/orm/decl_base.py", line 244, in _as_declarative
return MapperConfig.setup_mapping(registry, cls, dict, None, {})
File "/home/filippo/tmp/sqlmodel_mixin/venv/lib/python3.10/site-packages/sqlalchemy/orm/decl_base.py", line 325, in setup_mapping
return _ClassScanMapperConfig(
File "/home/filippo/tmp/sqlmodel_mixin/venv/lib/python3.10/site-packages/sqlalchemy/orm/decl_base.py", line 576, in init
self._setup_table(table)
File "/home/filippo/tmp/sqlmodel_mixin/venv/lib/python3.10/site-packages/sqlalchemy/orm/decl_base.py", line 1757, in _setup_table
table_cls(
File "", line 2, in new
File "/home/filippo/tmp/sqlmodel_mixin/venv/lib/python3.10/site-packages/sqlalchemy/util/deprecations.py", line 281, in warned
return fn(*args, **kwargs) # type: ignore[no-any-return]
File "/home/filippo/tmp/sqlmodel_mixin/venv/lib/python3.10/site-packages/sqlalchemy/sql/schema.py", line 430, in new
return cls._new(*args, **kw)
File "/home/filippo/tmp/sqlmodel_mixin/venv/lib/python3.10/site-packages/sqlalchemy/sql/schema.py", line 484, in _new
with util.safe_reraise():
File "/home/filippo/tmp/sqlmodel_mixin/venv/lib/python3.10/site-packages/sqlalchemy/util/langhelpers.py", line 146, in exit
raise exc_value.with_traceback(exc_tb)
File "/home/filippo/tmp/sqlmodel_mixin/venv/lib/python3.10/site-packages/sqlalchemy/sql/schema.py", line 480, in _new
table.init(name, metadata, *args, _no_init=False, **kw)
File "/home/filippo/tmp/sqlmodel_mixin/venv/lib/python3.10/site-packages/sqlalchemy/sql/schema.py", line 874, in init
self._init_items(
File "/home/filippo/tmp/sqlmodel_mixin/venv/lib/python3.10/site-packages/sqlalchemy/sql/schema.py", line 234, in _init_items
spwd(self, **kw)
File "/home/filippo/tmp/sqlmodel_mixin/venv/lib/python3.10/site-packages/sqlalchemy/sql/base.py", line 1324, in _set_parent_with_dispatch
self._set_parent(parent, **kw)
File "/home/filippo/tmp/sqlmodel_mixin/venv/lib/python3.10/site-packages/sqlalchemy/sql/schema.py", line 2337, in _set_parent
raise exc.ArgumentError(
sqlalchemy.exc.ArgumentError: Column object 'created_at' already assigned to Table 'mymodel'

It works using the mixin class just in one SqlModel model but this is not the intended use of a mixin class

Operating System

Linux

Operating System Details

No response

SQLModel Version

0.0.24

Python Version

3.10.12

Additional Context

(venv) filippo@dev101:~/tmp/sqlmodel_mixin$ pip freeze
annotated-types==0.7.0
greenlet==3.1.1
pydantic==2.10.6
pydantic_core==2.27.2
SQLAlchemy==2.0.39
sqlmodel==0.0.24
typing_extensions==4.13.0

[prietopa]

#743
Code run using "sa_type" instead "sa_column".

[filipposantovito]

changing sa_column to sa_type produces a different error:

Traceback (most recent call last):
  File "/home/filippo/tmp/sqlmodel_mixin/main.py", line 26, in <module>
    class MyModel(SQLModel, TimeStampMixin, table=True):
  File "/home/filippo/tmp/sqlmodel_mixin/venv/lib/python3.10/site-packages/sqlmodel/main.py", line 562, in __new__
    col = get_column_from_field(v)
  File "/home/filippo/tmp/sqlmodel_mixin/venv/lib/python3.10/site-packages/sqlmodel/main.py", line 760, in get_column_from_field
    return Column(sa_type, *args, **kwargs)  # type: ignore
  File "/home/filippo/tmp/sqlmodel_mixin/venv/lib/python3.10/site-packages/sqlalchemy/sql/schema.py", line 2168, in __init__
    self._init_items(*cast(_typing_Sequence[SchemaItem], l_args))
  File "/home/filippo/tmp/sqlmodel_mixin/venv/lib/python3.10/site-packages/sqlalchemy/sql/schema.py", line 234, in _init_items
    spwd(self, **kw)
  File "/home/filippo/tmp/sqlmodel_mixin/venv/lib/python3.10/site-packages/sqlalchemy/sql/base.py", line 1324, in _set_parent_with_dispatch
    self._set_parent(parent, **kw)
TypeError: Column._set_parent() missing 2 required keyword-only arguments: 'all_names' and 'allow_replacements'

are we using the same sqlmodel version?