小编Fre*_*joe的帖子

我有以下代码，我想做一个 upsert：

def add_electricity_reading(
    *, period_usage, period_started_at, is_estimated, customer_pk
):
    from sqlalchemy.dialects.postgresql import insert

    values = dict(
        customer_pk=customer_pk,
        period_usage=period_usage,
        period_started_at=period_started_at,
        is_estimated=is_estimated,
    )
    insert_stmt = insert(ElectricityMeterReading).values(**values)
    do_update_stmt = insert_stmt.on_conflict_do_update(
        constraint=ElectricityMeterReading.__table_args__[0].name,
        set_=dict(
            period_usage=period_usage,
            period_started_at=period_started_at,
            is_estimated=is_estimated,
        )
    )
    conn = DBSession.connection()
    conn.execute(do_update_stmt)

    return DBSession.query(ElectricityMeterReading).filter_by(**dict(
        period_usage=period_usage,
        period_started_at=period_started_at,
        customer_pk=customer_pk,
        is_estimated=is_estimated,
    )).one()

 def test_updates_existing_record_for_started_at_if_already_exists():
    started_at = datetime.now(timezone.utc)
    existing = add_electricity_reading(
        period_usage=0.102,
        customer_pk=customer.pk,
        period_started_at=started_at,
        is_estimated=True,
    )
    started_at = existing.period_started_at
    reading = add_electricity_reading(
        period_usage=0.200,
        customer_pk=customer.pk,
        period_started_at=started_at,
        is_estimated=True,
    )

    # existing record was updated
    assert reading.period_usage == 0.200
    assert …