为什么我不能使用 python 查询 Influxdbv2 数据？答案

【问题标题】：Why I cannot query Influxdbv2 data using python?为什么我不能使用 python 查询 Influxdbv2 数据？
【发布时间】：2021-03-28 21:50:47
【问题描述】：

我正在尝试使用 python3 从 InfluxDBv2 (2.0.2) 查询数据。查询在不断变化，它在 InfluxDB 中运行良好（它很好地显示了数据）。我尝试在同一个虚拟机（Ubuntu 18.04）和主机（Windows10 Jupyter python-kernel=python3）中执行。

!pip install influxdb-client
!pip install pandas
import pandas as pd
from influxdb_client import InfluxDBClient
client = InfluxDBClient(url="http://192.168.1.55:9999", token="RQrupr_Za863NcxjbWDWpVWgdgsgshwawkfYuPrc02tTvwCxwYOHywb_huoK4EttYY4pPOPr3Vcfv-7xo8cBlldw==", org="bim")
query_api=client.query_api()
data_frame = query_api.query_data_frame('from(bucket:"manager") |> range(start: v.timeRangeStart, stop: v.timeRangeStop) |> filter(fn: (r) => r["_measurement"] == "mqtt_consumer") |> filter(fn: (r) => r["_field"] == "timestamp") |> aggregateWindow(every: v.windowPeriod, fn: mean, createEmpty: false) |> yield(name: "mean")')
data_frame.head()

r@r-VirtualBox:~$ python qr.py
Traceback (most recent call last):
  File "qr.py", line 8, in <module>
    data_frame = query_api.query_data_frame('from(bucket:"manager") |> range(start: v.timeRangeStart, stop: v.timeRangeStop) |> filter(fn: (r) => r["_measurement"] == "mqtt_consumer") |> filter(fn: (r) => r["_field"] == "timestamp") |> aggregateWindow(every: v.windowPeriod, fn: mean, createEmpty: false) |> yield(name: "mean")')
  File "/home//.local/lib/python3.6/site-packages/influxdb_client/client/query_api.py", line 116, in query_data_frame
    _generator = self.query_data_frame_stream(query, org=org, data_frame_index=data_frame_index)
  File "/home/.local/lib/python3.6/site-packages/influxdb_client/client/query_api.py", line 141, in query_data_frame_stream
    async_req=False, _preload_content=False, _return_http_data_only=False)
  File "/home/.local/lib/python3.6/site-packages/influxdb_client/service/query_service.py", line 260, in post_query
    (data) = self.post_query_with_http_info(**kwargs)  # noqa: E501
  File "/home/.local/lib/python3.6/site-packages/influxdb_client/service/query_service.py", line 355, in post_query_with_http_info
    urlopen_kw=urlopen_kw)
  File "/home/.local/lib/python3.6/site-packages/influxdb_client/api_client.py", line 345, in call_api
    _preload_content, _request_timeout, urlopen_kw)
  File "/home/.local/lib/python3.6/site-packages/influxdb_client/api_client.py", line 174, in __call_api
    _request_timeout=_request_timeout, **urlopen_kw)
  File "/home/.local/lib/python3.6/site-packages/influxdb_client/api_client.py", line 392, in request
    **urlopen_kw)
  File "/home/.local/lib/python3.6/site-packages/influxdb_client/rest.py", line 309, in POST
    **urlopen_kw)
  File "/home/.local/lib/python3.6/site-packages/influxdb_client/rest.py", line 252, in request
    raise ApiException(http_resp=r)
influxdb_client.rest.ApiException: (400)
Reason: Bad Request
HTTP response headers: HTTPHeaderDict({'Content-Type': 'application/json; charset=utf-8', 'Vary': 'Accept-Encoding', 'X-Platform-Error-Code': 'invalid', 'Date': 'Fri, 18 Dec 2020 08:06:28 GMT', 'Transfer-Encoding': 'chunked'})
HTTP response body: b'{"code":"invalid","message":"error @1:219-1:220: undefined identifier v"}'

我错过了什么吗？我已经关注了这个官方网站的例子https://github.com/influxdata/influxdb-client-python#pandas-dataframe

【问题讨论】：

标签： python flux influxdb-2

【解决方案1】：

你读错了吗？

{"code":"invalid","message":"error @1:219-1:220: undefined identifier v"}

您的查询是

from(bucket:"manager") |> 
range(start: v.timeRangeStart, stop: v.timeRangeStop) |> 
filter(fn: (r) => r["_measurement"] == "mqtt_consumer") |> 
filter(fn: (r) => r["_field"] == "timestamp") |> 
aggregateWindow(every: v.windowPeriod, fn: mean, createEmpty: false) |> 
yield(name: "mean")

但您从未以任何方式定义在range 和aggregateWindow 子句中使用的v 变量。

它们可能在其他一些 InfluxDB 客户端中工作，因为它的 UI 定义了它们，并可能在将查询传递给 InfluxDB 服务器之前将它们替换到查询中。

【讨论】：