Foreign key with ondelete set null

[jfernandez-majorel]

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Example Code

class UUIDModel(SQLModel):
    uuid: uuid_pkg.UUID = Field(
        default_factory=uuid_pkg.uuid4,
        primary_key=True,
        index=True,
        nullable=False,
        sa_column_kwargs={
            "server_default": text("gen_random_uuid()"),
            "unique": True,
        },
    )

class Client(UUIDModel, SQLModel):
    number_login: str = Field(max_length=20, nullable=False, index=True)
    uuid_fiber_appointment: Optional[uuid_pkg.UUID] = Field(
        foreign_key="fiber_appointment.uuid",
        nullable=True,
    )
    fiber_appointment: "FiberAppointment" = Relationship(
        back_populates="clients",
        sa_relationship_kwargs={"lazy": "selectin"},
    )

class FiberAppointment(
    UUIDModel,
    SQLModel,
    table=True,
):
    __tablename__ = "fiber_appointment"
    appointment_datetime: datetime
    clients: List["Client"] = Relationship(
        back_populates="fiber_appointment",
    )

Description

I need to delete a list of appointments and that the clients that had those appointments, in the foreign key field (uuid_fiber_appointment) be set to null

Operating System

macOS

Operating System Details

No response

SQLModel Version

0.0.8

Python Version

Python 3.10.11

Additional Context

No response

[FilipeMarch]

@jfernandez-majorel

Have you tried adding "cascade": "" to sa_relationship_kwargs?

class Client(UUIDModel, SQLModel):
    number_login: str = Field(max_length=20, nullable=False, index=True)
    uuid_fiber_appointment: Optional[uuid_pkg.UUID] = Field(
        foreign_key="fiber_appointment.uuid",
        nullable=True,
    )
    fiber_appointment: "FiberAppointment" = Relationship(
        back_populates="clients",
        sa_relationship_kwargs={"lazy": "selectin", "cascade": ""},
    )

Try it

[YuriiMotov]

Related section of docs: https://sqlmodel.tiangolo.com/tutorial/relationship-attributes/cascade-delete-relationships/#ondelete-with-set-null