* 用例1：计算可转债市场分钟平均交易量
```
import dai
df = dai.query("""
SELECT
date, AVG(volume) as avg_volume
FROM cn_cbond_bar1m
GROUP BY date
ORDER BY date""",
filters={"date": ["2023-01-01", "2024-01-05"]}
).df()
```
* 用例2：计算某只可转债分钟价格变动百分比
```
import dai
df = dai.query("""
SELECT
date, instrument, ((close - open) / open) * 100 as price_change_percentage
FROM cn_cbond_bar1m
WHERE instrument = '127025.SZ'
ORDER BY date""",
filters={"date": ["2023-01-01", "2024-01-05"]}
).df()
```