title: JQ - Cannot extract values from Ubibot json
body: <p>I have a Ubibot ws-1 and I'm trying to extract Timestamp, Temperature, Humidity, Light and voltage from <code>last_values</code> in the following JSON</p>
  
  <p>The API JSON output is</p>
  
  <pre><code>{
    "channel": {
      "channel_id": "1111",
      "name": "C-1111",
      "field1": "Temperature",
      "field2": "Humidity",
      "field3": "Light",
      "field4": "Voltage",
      "field5": "WIFI RSSI",
      "field6": "Vibration Index",
      "field7": "Knocks",
      "field8": "External Temperature Probe",
      "field9": "Reed Sensor",
      "field10": null,
      "latitude": "1",
      "longitude": "1",
      "elevation": null,
      "created_at": "2019-02-05T05:16:43Z",
      "updated_at": "2019-02-05T06:11:38Z",
      "metadata": "{\"fn_dp\":900,\"fn_th\":300,\"fn_light\":300,\"fn_acc_act\":0,\"thres_acc_min\":0,\"fn_acc_tap1\":0,\"fn_acc_tap2\":0,\"fn_ext_t\":300,\"fn_battery\":7200,\"fn_485_th\":0,\"fn_485_sth\":0,\"net_mode\":0,\"no_net_fn\":1,\"cg_data_led\":1,\"wifi_mode\":1}",
      "tags": null,
      "public_flag": "false",
      "url": null,
      "description": null,
      "write_key": "1b0f2b31a6d522a376782a90f4be0270",
      "user_id": "9186F150-9203-492B-B31A-77077E15E461",
      "last_entry_id": "583",
      "last_entry_date": "2019-02-05T19:12:47Z",
      "usage": "96328",
      "device_id": "17a867e84624895f6dab0346a4cba8cfd8279298",
      "status": "{\"ssid\":\"hydra1\",\"status\":\"ssid=wifi,usb=1\",\"usb\":\"1\"}",
      "status_date": "1549393967",
      "last_ip": "nn.nn.nn.nnn",
      "channel_icon": null,
      "product_id": "ubibot-ws1",
      "plan_code": "ubibot_free",
      "plan_start": "2019-02-05T05:16:43Z",
      "plan_end": null,
      "bill_start": "2019-02-05T05:16:43Z",
      "bill_end": "2019-03-07T05:16:43Z",
      "traffic_out": "188763",
      "traffic_in": "33767",
      "full_dump": "0",
      "renew": null,
      "last_values": "{\"field1\":{\"value\":27.186996,\"created_at\":\"2019-02-05T19:12:39Z\"},\"field3\":{\"value\":10.37,\"created_at\":\"2019-02-05T19:12:39Z\"},\"field2\":{\"value\":29,\"created_at\":\"2019-02-05T19:12:39Z\"},\"field5\":{\"value\":-35,\"created_at\":\"2019-02-05T19:12:41Z\"},\"field4\":{\"value\":5,\"created_at\":\"2019-02-05T17:27:38Z\"}}",
  
    }
  }
  </code></pre>
  
  <p>my jq skills are very poor <code>.channel.last_values."\(.field1)</code> gives me <code>jq: error (at &lt;stdin&gt;:0): Cannot index string with string "null"</code>.</p>
  
  <p>Can someone help me with the correct jq? Thanks in advance</p>