node-red-node-tdengine

TDengine Integration with Node-RED

• TDengine Integration with Node-RED
  • Overview
  • Features
    • tdengine-operator
    • tdengine-consumer
  • Prerequisites
  • Configure Data Source
  • Installation
  • Node Status
  • Input Format
    • tdengine-operator
    • tdengine-consumer
  • Output Format
    • tdengine-operator
    • tdengine-consumer
  • Quick Start
    • Input
    • Output
  • Documents
  • Resources

Overview

Node-RED is an open-source visual programming tool developed by IBM based on Node.js. It enables users to assemble and connect various nodes via a graphical interface to create connections for IoT devices, APIs, and online services. Supporting multi-protocol and cross-platform capabilities, it has an active community and is ideal for event-driven application development in smart home, industrial automation, and other scenarios, with its main strengths being low-code and visual programming.

The deep integration between TDengine and Node-RED provides a comprehensive solution for industrial IoT scenarios. Through Node-RED's MQTT/OPC UA/Modbus protocol nodes, data from PLCs, sensors and other devices can be collected at millisecond-level speed. Real-time queries of TDengine can trigger physical control actions like relay operations and valve switching for immediate command execution.

node-red-node-tdengine is the official plugin developed by TDengine for Node-RED. Composed of two nodes:

• tdengine-operator: Provides SQL execution capabilities for data writing/querying and metadata management.
• tdengine-consumer: Offers data subscription and consumption capabilities from specified subscription servers and topics.

Features

tdengine-operator

• Supports TDengine local deployment or cloud service data sources.
• Full coverage of all TDengine SQL operations (SELECT/INSERT/CREATE/ALTER/SHOW, etc.).
• Unified interface for handling both read and write operations using msg.topic to pass SQL statements.

tdengine-consumer

• Support TDengine local deployment or cloud service data sources.
• Flexible configuration of subscription properties.
• Support subscribing to multiple topics simultaneously.
• Automatically submit and save consumption progress.
• Automatically reconnect after server disconnection.

Prerequisites

Prepare the following environment:

• TDengine >= 3.3.2.0 (Enterprise/Community/Cloud Edition are available).
• taosAdapter is running, refer to taosAdapter.
• Node-RED >= 3.0.0, Node-RED installation.
• Node.js Connector for TDengine >= 3.1.8, get from npmjs.com.

Configure Data Source

TDengine WebSocket connection string format:

• tdengine-operator: ws://user:password@host:port
• tdengine-consumer: ws://host:port

See detail here.

Installation

Run the following command in your Node-RED user directory - typically ~/.node-red .

  npm i node-red-node-tdengine

Node Status

• Grey: Connecting.
• Green: Operational.
• Red: Malfunction.

Input Format

tdengine-operator

Pass SQL statement via topic:

msg = { topic: "SQL statement" }

Special characters and escape sequences in SQL must follow JSON string specifications.

tdengine-consumer

Input node (no input).

Output Format

tdengine-operator

• Write Operations
  The payload contains write results, and the topic passes through the SQL statement:

  msg = {
  topic: "insert into ...",
  isQuery: false, // true for query operations
  payload: {
  affectRows: 2,  // affect rows
  totalTime: 3,   // Total write time (ms)
  timing: 1683311 // Server-side execution time (ns)
  }
  }
  

• Query Operations
  payload contains query results, topic passes through SQL:

  {
  topic: "select * from ...",
  isQuery: true, // true for query operations
  payload: [
  { ts: 1749609744000, current: 20, voltage: 200, phase: 5 },
  { ts: 1749609200001, current: 31, voltage: 210, phase: 4 },
      ...
  ]}
  

Query results are row data objects where properties correspond to column names. For data type mappings: TDengine NodeJS Connector Type Mapping.

tdengine-consumer

payload outputs array of objects where properties correspond to column names: TDengine NodeJS Connector Type Mapping.

{
  topic: Subscription topic,
  database: Database name,
  vgroup_id: Data partition,
  precision: Database precision
  payload: [{ 
    column_name1: value1,
    column_name2: value2,
    ...
  },
  ...
  ],
}

Quick Start

Input

// Example: Inserting data
msg.topic = "insert into test.d0 values ('2025-06-10 10:00:02.001', 23.5, 220, 3)";
return msg;

// Example: Querying data
msg.topic = "select * from test.d0";
return msg;

Output

• Insert Result

  {
  "topic":  "insert into test.d0 values ('2025-06-10 10:00:02.001', 23.5, 220, 3)",
  "_msgid": "8f50fe84338387d7",
  "isQuery": false,
  "payload":{
      "affectRows": 1,
      "totalTime":  2,
      "timing":     "961982"
  }
  }
  

• Query Result

  {
  "topic":  "select * from test.d0",
  "_msgid": "0d19e9b82ae3841a",
  "isQuery":  true,
  "payload": [
    { "ts": 1749609744000, "current": 10, "voltage": 219, "phase": 0.32 },
    { "ts": 1749609200001, "current": 31, "voltage": 210, "phase": 4 }
  ]
  }
  

• Subscribe Result

  {
  "topic": "topic_overload",
  "payload": [
      {
      "tbname":   "d1",
      "ts":       "1750140456777",
      "current":  31,
      "voltage":  217,
      "phase":    2,
      "groupid":  4,
      "location": "California.MountainView"
      }
  ],
  "database":  "test",
  "vgroup_id": 4,
  "precision": 0
  }
  

Documents

• Full documentation is available in Node-RED's in-editor help system (click the book icon).
• Introduce usage scenarios with Node-RED Plugin for TDengine.

Resources

• TDengine Official Website.
• Node.js Connector for TDengine.