* 用例1：分析指定日期范围内的特定可转债交易行情
```
import dai
df = dai.query("""
SELECT
date, instrument, volume, amount, high, low, open, close
FROM cn_cbond_bar1d
WHERE instrument='128141.SZ'
ORDER BY date""",
filters={"date": ["2023-01-01", "2024-01-31"]}
).df()
```
* 用例2：使用可转债和其对应正股的收盘价数据，分析两者的价格相关性
```
import dai
df = dai.query("""
SELECT
a.date, a.instrument, a.stock, a.close AS bond_close, b.close AS stock_close
FROM cn_cbond_bar1d AS a
JOIN cn_stock_bar1d AS b
ON a.stock = b.instrument AND a.date = b.date
ORDER BY a.date""",
filters={"date": ["2023-01-01", "2024-01-31"]}
).df()
df
```