Error when using Relationships with one-to-one models

First Check

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• 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.

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Example Code

class User(UserBase, table=True):
    __tablename__ = "users"

    id: uuid.UUID = Field(
        default_factory=uuid.uuid4,
        primary_key=True,
        index=True,
        nullable=False,
    )

    contact_info: Optional["ContactInfo"] = Relationship(
        sa_relationship=RelationshipProperty(
            "ContactInfo", uselist=False, back_populates="user"
        ),
    )

class ContactInfo(ContactInfoBase, table=True):
    __tablename__ = "contact_info"

    id: uuid.UUID = Field(
        default_factory=uuid.uuid4,
        primary_key=True,
        index=True,
        nullable=False,
    )

    # Connect to users table
    user_id: uuid.UUID = Field(default=None, foreign_key="users.id")
    user: User = Relationship(back_populates="contact_info")

class Repository:
    def __init__(self, *, user_repository: UserRepository = Depends()):
        self.user_repository = user_repository

    def create_contact_info(
        self,
        *,
        session: Session,
        contact_info_create: ContactInfoCreate,
        user: User,
    ) -> ContactInfo:
        db_contact_info = ContactInfo.from_orm(contact_info_create)
        db_contact_info.user = user

        session.add(db_contact_info)
        session.commit()
        session.refresh(db_contact_info)
        return db_contact_info

Description

An exception is raised when trying to set the user field on the ContactInfo.

I have attempted to follow the instructions from sqlalchemy about one-to-one, though there is no documentation on that kind of relationship from SQLModel.

Traceback (most recent call last):
  File "/usr/local/lib/python3.9/site-packages/uvicorn/protocols/http/httptools_impl.py", line 375, in run_asgi
    result = await app(self.scope, self.receive, self.send)
  File "/usr/local/lib/python3.9/site-packages/uvicorn/middleware/proxy_headers.py", line 75, in __call__
    return await self.app(scope, receive, send)
  File "/usr/local/lib/python3.9/site-packages/fastapi/applications.py", line 208, in __call__
    await super().__call__(scope, receive, send)
  File "/usr/local/lib/python3.9/site-packages/starlette/applications.py", line 112, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/usr/local/lib/python3.9/site-packages/starlette/middleware/errors.py", line 181, in __call__
    raise exc from None
  File "/usr/local/lib/python3.9/site-packages/starlette/middleware/errors.py", line 159, in __call__
    await self.app(scope, receive, _send)
  File "/usr/local/lib/python3.9/site-packages/starlette/middleware/cors.py", line 86, in __call__
    await self.simple_response(scope, receive, send, request_headers=headers)
  File "/usr/local/lib/python3.9/site-packages/starlette/middleware/cors.py", line 142, in simple_response
    await self.app(scope, receive, send)
  File "/usr/local/lib/python3.9/site-packages/starlette/exceptions.py", line 82, in __call__
    raise exc from None
  File "/usr/local/lib/python3.9/site-packages/starlette/exceptions.py", line 71, in __call__
    await self.app(scope, receive, sender)
  File "/usr/local/lib/python3.9/site-packages/starlette/routing.py", line 580, in __call__
    await route.handle(scope, receive, send)
  File "/usr/local/lib/python3.9/site-packages/starlette/routing.py", line 241, in handle
    await self.app(scope, receive, send)
  File "/usr/local/lib/python3.9/site-packages/starlette/routing.py", line 52, in app
    response = await func(request)
  File "/usr/local/lib/python3.9/site-packages/fastapi/routing.py", line 226, in app
    raw_response = await run_endpoint_function(
  File "/usr/local/lib/python3.9/site-packages/fastapi/routing.py", line 161, in run_endpoint_function
    return await run_in_threadpool(dependant.call, **values)
  File "/usr/local/lib/python3.9/site-packages/starlette/concurrency.py", line 40, in run_in_threadpool
    return await loop.run_in_executor(None, func, *args)
  File "/usr/local/lib/python3.9/concurrent/futures/thread.py", line 52, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/app/./app/api/routes/kyc.py", line 43, in create_contact_info
    kyc_repository.create_contact_info(
  File "/app/./app/api/repositories/kyc_repository.py", line 28, in create_contact_info
    db_contact_info.user = user
  File "/usr/local/lib/python3.9/site-packages/sqlmodel/main.py", line 516, in __setattr__
    set_attribute(self, name, value)
  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/orm/attributes.py", line 2240, in set_attribute
    state.manager[key].impl.set(state, dict_, value, initiator)
  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/orm/attributes.py", line 1253, in set
    value = self.fire_replace_event(state, dict_, value, old, initiator)
  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/orm/attributes.py", line 1279, in fire_replace_event
    value = fn(
  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/orm/attributes.py", line 1714, in emit_backref_from_scalar_set_event
    instance_state(child),
AttributeError: Could not locate column in row for column '_sa_instance_state'

Operating System

macOS

Operating System Details

No response

SQLModel Version

0.0.4

Python Version

3.9.7

Additional Context

No response

[br-allstreet]

Indeed, I was able to work around the issue by setting the relevant fields using the SQLAlchemy conventions, instead of SQLModel:

class User(UserBase, table=True):
    __tablename__ = "users"

    id: uuid.UUID = Field(
        default_factory=uuid.uuid4,
        primary_key=True,
        index=True,
        nullable=False,
    )
    contact_info: Optional["ContactInfo"] = Relationship(
        sa_relationship=RelationshipProperty(
            "ContactInfo", back_populates="user", uselist=False
        ),
    )

class ContactInfo(ContactInfoBase, table=True):
    user_id: uuid.UUID = Field(
        sa_column=Column("user_id", ForeignKey("users.id"), nullable=False)
    )
    user: User = Relationship(
        sa_relationship=RelationshipProperty("User", back_populates="contact_info")
    )

[arkryonia]

Indeed, I was able to work around the issue by setting the relevant fields using the SQLAlchemy conventions, instead of SQLModel:

class User(UserBase, table=True):
    __tablename__ = "users"

    id: uuid.UUID = Field(
        default_factory=uuid.uuid4,
        primary_key=True,
        index=True,
        nullable=False,
    )
    contact_info: Optional["ContactInfo"] = Relationship(
        sa_relationship=RelationshipProperty(
            "ContactInfo", back_populates="user", uselist=False
        ),
    )

class ContactInfo(ContactInfoBase, table=True):
    user_id: uuid.UUID = Field(
        sa_column=Column("user_id", ForeignKey("users.id"), nullable=False)
    )
    user: User = Relationship(
        sa_relationship=RelationshipProperty("User", back_populates="contact_info")
    )

It works! Good Job @brapaport !