@classmethod
    def assignment_ondelete(cls, row):
        """
            Ondelete callback for work assignments

            @param row: the Row
        """

        try:
            record_id = row.id
        except __HOLE__:
            return

        db = current.db
        atable = current.s3db.work_assignment

        row = db(atable.id == record_id).select(atable.deleted_fk,
                                                limitby = (0, 1)).first()

        if row and row.deleted_fk:
            data = json.loads(row.deleted_fk)
            job_id = data.get("job_id")
            if job_id:
                cls.update_workers_assigned(job_id)

        return

    # -------------------------------------------------------------------------
dataset/ETHPy150Open sahana/eden/modules/s3db/work.py/WorkJobModel.assignment_ondelete