时序数据表始终相对于第一行/天计算增减百分比

import pandas as pd

# 假设df是一个Pandas DataFrame，其中包含时序数据
df = pd.DataFrame({
    'date': ['2023-01-01', '2023-01-02', '2023-01-03'],
    'value': [100, 120, 90]
})

# 计算增减百分比
base_value = df.loc[0, 'value']
df['percentage_change'] = ((df['value'] - base_value) / base_value) * 100

print(df)

         date  value  percentage_change
0  2023-01-01    100               0.00
1  2023-01-02    120               20.00
2  2023-01-03     90              -10.00

# 处理基线为零的情况
if base_value == 0:
    base_value = 0.01

df['percentage_change'] = ((df['value'] - base_value) / base_value) * 100

-- 假设数据存储在名为time_series_data的表中
SELECT date, value,
       ((value - (SELECT value FROM time_series_data WHERE date = '2023-01-01')) / (SELECT value FROM time_series_data WHERE date = '2023-01-01')) * 100 AS percentage_change
FROM time_series_data;