从连接的SQLAlchemy查询构造数据框

Question

来自查询的

：

 session.query(Record, RecordMeasurement).filter(Record.record_pkid==RecordMeasurement.record_fkid)

我想构建1个数据框，其中包含Record列的值：

['datetime', 'record_number']

和RecordMeasurement列：

['power', 'voltage', 'temperature']

数据帧列顺序无关紧要。

Answer 1

将您的查询更改为只包含您需要的列：

query = (session.query(
    Record.datetime, Record.record_number, 
    RecordMeasurement.power, RecordMeasurement.voltage, RecordMeasurement.temperature,
    )
    .filter(Record.record_pkid==RecordMeasurement.record_fkid)
)

然后致电：

import pandas as pd
# ...
df = pd.read_sql(query.statement, query.session.bind)