Method __init__

sqlmodel/main.py:627–683

(
        cls, classname: str, bases: tuple[type, ...], dict_: dict[str, Any], **kw: Any
    )

    # Override SQLAlchemy, allow both SQLAlchemy and plain Pydantic models
    def __init__(
        cls, classname: str, bases: tuple[type, ...], dict_: dict[str, Any], **kw: Any
    ) -> None:
        # Only one of the base classes (or the current one) should be a table model
        # this allows FastAPI cloning a SQLModel for the response_model without
        # trying to create a new SQLAlchemy, for a new table, with the same name, that
        # triggers an error
        base_is_table = any(is_table_model_class(base) for base in bases)
        if is_table_model_class(cls) and not base_is_table:
            for rel_name, rel_info in cls.__sqlmodel_relationships__.items():
                if rel_info.sa_relationship:
                    # There's a SQLAlchemy relationship declared, that takes precedence
                    # over anything else, use that and continue with the next attribute
                    setattr(cls, rel_name, rel_info.sa_relationship)  # Fix #315
                    continue
                raw_ann = cls.__annotations__[rel_name]
                origin: Any = get_origin(raw_ann)
                if origin is Mapped:
                    ann = raw_ann.__args__[0]
                else:
                    ann = raw_ann
                    # Plain forward references, for models not yet defined, are not
                    # handled well by SQLAlchemy without Mapped, so, wrap the
                    # annotations in Mapped here
                    cls.__annotations__[rel_name] = Mapped[ann]
                relationship_to = get_relationship_to(
                    name=rel_name, rel_info=rel_info, annotation=ann
                )
                rel_kwargs: dict[str, Any] = {}
                if rel_info.back_populates:
                    rel_kwargs["back_populates"] = rel_info.back_populates
                if rel_info.cascade_delete:
                    rel_kwargs["cascade"] = "all, delete-orphan"
                if rel_info.passive_deletes:
                    rel_kwargs["passive_deletes"] = rel_info.passive_deletes
                if rel_info.link_model:
                    ins = inspect(rel_info.link_model)
                    local_table = getattr(ins, "local_table")  # noqa: B009
                    if local_table is None:
                        raise RuntimeError(
                            "Couldn't find the secondary table for "
                            f"model {rel_info.link_model}"
                        )
                    rel_kwargs["secondary"] = local_table
                rel_args: list[Any] = []
                if rel_info.sa_relationship_args:
                    rel_args.extend(rel_info.sa_relationship_args)
                if rel_info.sa_relationship_kwargs:
                    rel_kwargs.update(rel_info.sa_relationship_kwargs)
                rel_value = relationship(relationship_to, *rel_args, **rel_kwargs)
                setattr(cls, rel_name, rel_value)  # Fix #315
            # SQLAlchemy no longer uses dict_
            # Ref: https://github.com/sqlalchemy/sqlalchemy/commit/428ea01f00a9cc7f85e435018565eb6da7af1b77
            # Tag: 1.4.36
            DeclarativeMeta.__init__(cls, classname, bases, dict_, **kw)
        else:
            ModelMetaclass.__init__(cls, classname, bases, dict_, **kw)