join语句中Flux脚本面临的问题

Question

尝试连接两个数据流时，我遇到以下异常：

influxdb_client.rest.ApiException: (500)
Reason: Internal Server Error
HTTP response headers: HTTPHeaderDict({'Content-Type': 'application/json', 'Request-Id': 'b1dc2aa4-b6f3-11eb-8060-0242ac110002', 'X-Influxdb-Build': 'OSS', 'X-Influxdb-Error': 'failed to compile query: type error 1:21-1:29: undefined identifier "cpupower"', 'X-Influxdb-Version': '1.7.6', 'X-Request-Id': 'b1dc2aa4-b6f3-11eb-8060-0242ac110002', 'Date': 'Mon, 17 May 2021 09:38:54 GMT', 'Content-Length': '93'})
HTTP response body: b'{"error":"failed to compile query: type error 1:21-1:29: undefined identifier \\"cpupower\\""}\n'

---

代码片段是：

query_api = client.query_api()

query = 'from(bucket: "metrics")\
        |> range(start: 00000000)\
        |> filter(fn: (r) => r._measurement == "TotalCPUPower" and r._field =~ /time|Server|value/)\
        |> pivot(rowKey:["_time"], columnKey: ["_field"], valueColumn: "_value")'

cpupower = client.query_api().query(org=org, query=query)

fpgapower = 'from(bucket: "metrics")\
        |> range(start: 00000000)\
        |> filter(fn: (r) => r._measurement == "TotalFPGAPower" and r._field =~ /time|Server|value/)\
        |> pivot(rowKey:["_time"], columnKey: ["_field"], valueColumn: "_value")'

fpgapower = client.query_api().query(org=org, query=query)

query = 'join(tables: {tab1: cpupower, tab2: fpgapower}, on: ["_time"])'