Method _delete_fk_sql

django/db/backends/base/schema.py:1792–1793

(self, model, name)

        )

    def _delete_fk_sql(self, model, name):
        return self._delete_constraint_sql(self.sql_delete_fk, model, name)

    def _deferrable_constraint_sql(self, deferrable):
        if deferrable is None: