s: ModelSelect = (
DbBarData.select().where(
(DbBarData.symbol == symbol)
& (DbBarData.exchange == exchange.value)
& (DbBarData.interval == interval.value)
& (DbBarData.datetime <= end)
).order_by(DbBarData.datetime).limit(count)
)
想取最新的count条数据,就要排序,在哪里加上 DESC呢