#6 監測資料寫入InfluxDB資料庫, 長期保存並在NodeRED資訊看板裡顯示

Format code for writing InfluxDB

// Create the object key to match DB filed name from topic name(studio/temp1)
msg.payload["temp"] = msg.payload["studio/temp1"];
// Delete the unwanted studio/temp1
delete msg.payload["studio/temp1"];
// Update temp from string to float
msg.payload["temp"] = parseFloat(msg.payload["temp"]);

msg.payload["humd"] = msg.payload["studio/humd1"];
delete msg.payload["studio/humd1"];
msg.payload["humd"] = parseFloat(msg.payload["humd"]);

//remove unused topic
delete msg.topic;

//Create a temporary array
var data = [];
data.push(msg.payload);


//Add object to DB Tag(index field)
data.push({"location":"studio"});
//msg.payload.push({"location":"studio"});

//Copy temporary array to msg.payload
msg.payload = data;
return msg;

Format code for reading historical InfluxDB data

//Source from: https://discourse.nodered.org/t/display-2-extracts-from-influxdb-in-an-ui-chart/29665
var series = ["Temperature °C", "Humdity %"];
var labels = ["temp", "Humdity"];

var data0 = "[";
var thetime0;

for (var i=0; i < msg.payload.results[0].series[0].values.length; i++) {
thetime0 = (msg.payload.results[0].series[0].values[i][0]); // Some manipulation of the time may be required
thetime0 = Date.parse(thetime0);
data0 += '{ "x":' + thetime0 + ', "y":' + (msg.payload.results[0].series[0].values[i][1]) + '}';
if (i < (msg.payload.results[0].series[0].values.length - 1)) {
data0 += ","
} else {
data0 += "]"
}
}



var data1 = "[";
var thetime1;

for (var j=0; j < msg.payload.results[0].series[0].values.length; j++) {
thetime1 = (msg.payload.results[0].series[0].values[j][0]); // Some manipulation of the time may be required
thetime1 = Date.parse(thetime1);
data1 += '{ "x":' + thetime1 + ', "y":' + (msg.payload.results[0].series[0].values[j][2]) + '}';
if (j < (msg.payload.results[0].series[0].values.length - 1)) {
data1 += ","
} else {
data1 += "]"
}
}
var data = [data0, data1];
var jsondata = [JSON.parse(data0), JSON.parse(data1)];
msg.payload = [{"series": series, "data": jsondata, "labels": labels}];
msg.dataPoints = data;


return msg;

請在此下載本篇教學的 NodeRead 程式： #6 監測資料寫入InfluxDB資料庫, 長期保存並在NodeRED資訊看板裡顯示

InfluxDB out node 內容有兩項資料要輸入：

(1) 定義 InfluxDB Server, 按下鉛筆符號(見下圖）

(2) 寫入的 Measurement 資料表名稱，我們的範例裡，Measurement = studioTemp

定義 InfluxDB Server：

(5) 資料庫帳號及密碼： 如果未設定可略過

Stonez56 一起來學樹莓派系列影片: 

• #1 無鍵盤 無滑鼠 快速上手
  https://youtu.be/BCkdSQNtVB0 
• #2 改用 USB3/SSD 來開機, 畫面好流暢!
  https://youtu.be/uI01GFmfH1k
• #3 一行指令安裝 Node RED & 外加密碼保護       
  https://youtu.be/Mk8-xn_fHOA 
• #4 安裝 Mosquitto broker (MQTT) & 並在Node-RED & Google MQTTLens 進行測試 https://youtu.be/cK_LJPgR4mQ
• #5 溫溼度感測器DHT11由 ESP32 經 MQTT 送到 Node-RED
  https://youtu.be/Vv1JRNYIZKc 
• #6 監測資料寫入InfluxDB資料庫, 長期保存並在NodeRED資訊看板裡顯示 https://youtu.be/UOoDolPVge0 
• #7 2021 一起來學樹莓派 – 動態查詢InfluxDB 資料庫 & MQTT來遠端開/關繼電器  https://youtu.be/EpY_jl4wXtM