How to delete in cascade?

[pawamoy]

I have this route:

@router.delete("/{team_id}")
async def delete_team(team_id: int) -> None:
    team = await Team.objects.get(pk=team_id)
    await team.delete()

Other objects in the database have foreign keys pointing to teams.
When I call this route, I get this:

{
  "error": "integrity error",
  "details": "FOREIGN KEY constraint failed"
}

The response is coming from this handler:

@app.exception_handler(sqlite3.IntegrityError)
async def integrity_error_handler(request: Request, exc: sqlite3.IntegrityError) -> JSONResponse:
    return JSONResponse(
        status_code=400,
        content={"error": "integrity error", "details": str(exc)},
    )

I searched for "cascade" in the docs but couldn't find anything. Was I supposed to set ondelete="cascade" somewhere in the models?

[pawamoy]

Ah, I see, it's here: https://collerek.github.io/ormar/api/fields/foreign-key/#populate_fk_params_based_on_to_model
Still not sure what value I should put in ondelete=... 😕

[collerek]

Hmm maybe I missed that in the docs, you can pass ondelete and onupdate in ForeignKey like:

source: Optional[DataSource] = ormar.ForeignKey(DataSource, ondelete="CASCADE")

If you want to cascades the delete then use.. CASCADE :)
Those options are passed to sqlalchemy so you can check available options there.

[pawamoy]

Thanks !
A link to the accepted values on SQLAlchemy's docs would be very handy 😄

[collerek]

https://docs.sqlalchemy.org/en/14/core/constraints.html#on-update-and-on-delete :)