我把bars的数据导入mysql，返回时true,但是实际数据库没有数据，这是为什么？代码如下:
bars = []
for index, row in df.iterrows():
dt = row['date']

if isinstance(dt, pd.Timestamp) or hasattr(dt, 'to_pydatetime'):
    dt = dt.to_pydatetime()
# 如果 dt 是 naive datetime（无时区信息），使用 replace 添加时区
if dt.tzinfo is None:
    dt_aware = dt.replace(tzinfo=DB_TZ)
else:
    dt_aware = dt.astimezone(DB_TZ)
bar = BarData(
    symbol = '300036招商银行',
    exchange = Exchange.SZSE,
    datetime = dt_aware,
    interval = Interval.DAILY,
    open_price = row['open'],
    high_price = row['high'],
    low_price = row['low'],
    close_price = row['close'],
    volume = row['volume'],
    open_interest = 0.0,
    gateway_name = "DB"
)
bars.append(bar)

存入数据库

database_manager.save_bar_data(bars)