08-node.mdx

---
toc_max_heading_level: 4
sidebar_label: Node.js
title: TDengine Node.js Connector
---

import Tabs from "@theme/Tabs";
import TabItem from "@theme/TabItem";

import Preparition from "./_preparition.mdx";
import NodeInsert from "../../07-develop/03-insert-data/_js_sql.mdx";
import NodeInfluxLine from "../../07-develop/03-insert-data/_js_line.mdx";
import NodeOpenTSDBTelnet from "../../07-develop/03-insert-data/_js_opts_telnet.mdx";
import NodeOpenTSDBJson from "../../07-develop/03-insert-data/_js_opts_json.mdx";
import NodeQuery from "../../07-develop/04-query-data/_js.mdx";

`@tdengine/client` and `@tdengine/rest` are the official Node.js connectors. Node.js developers can develop applications to access TDengine instance data. Note: The connectors for TDengine 3.0 are different than those for TDengine 2.x. The new connectors do not support TDengine 2.x.

`@tdengine/client` is **native connection**, which connects to TDengine instances natively through the TDengine client driver (taosc), supporting data writing, querying, subscriptions, schemaless writing, and bind interface. `@tdengine/rest` is the **REST connection**, which connects to TDengine instances via the REST interface provided by taosAdapter. The REST connector can run on any platform, but performance is slightly degraded, and the interface implements a somewhat different set of functional features than the native interface.

The source code for the Node.js connectors is located on [GitHub](https://github.com/taosdata/taos-connector-node/tree/3.0).

## Supported platforms

The platforms supported by the native connector are the same as those supported by the TDengine client driver.
The REST connector supports all platforms that can run Node.js.

## Version support

Please refer to [version support list](/reference/connector#version-support)

## Supported features

### Native connectors

1. Connection Management
2. General Query
3. Continuous Query
4. Parameter Binding
5. Subscription
6. Schemaless

### REST Connector

1. Connection Management
2. General Query
3. Continuous Query

## Installation Steps

### Pre-installation preparation

- Install the Node.js development environment
- If you are using the REST connector, skip this step. However, if you use the native connector, please install the TDengine client driver. Please refer to [Install Client Driver](/reference/connector#Install-Client-Driver) for more details. We use [node-gyp](https://github.com/nodejs/node-gyp) to interact with TDengine instances and also need to install some dependencies mentioned below depending on the specific OS.

<Tabs defaultValue="Linux">
<TabItem value="Linux" label="Linux system installation dependencies">

- `python` (recommended for `v2.7` , `v3.x.x` currently not supported)
- `@tdengine/client` 3.0.0 supports Node.js LTS v10.9.0 or later and Node.js LTS v12.8.0 or later. Older versions may be incompatible.
- `make`
- C compiler, [GCC](https://gcc.gnu.org) v4.8.5 or higher

</TabItem>
<TabItem value="Windows" label="Windows system installation dependencies">

- Installation method 1

Use Microsoft's [windows-build-tools](https://github.com/felixrieseberg/windows-build-tools) to execute `npm install --global --production` from the `cmd` command-line interface to install all the necessary tools.

- Installation method 2

Manually install the following tools.

- Install Visual Studio related: [Visual Studio Build Tools](https://visualstudio.microsoft.com/thank-you-downloading-visual-studio/?sku=BuildTools) or [Visual Studio 2017 Community](https://visualstudio.microsoft.com/pl/thank-you-downloading-visual-studio/?sku=Community)
- Install [Python](https://www.python.org/downloads/) 2.7 (`v3.x.x` is not supported) and execute `npm config set python python2.7`.
- Go to the `cmd` command-line interface, `npm config set msvs_version 2017`

Refer to Microsoft's Node.js User Manual [Microsoft's Node.js Guidelines for Windows](https://github.com/Microsoft/nodejs-guidelines/blob/master/windows-environment.md#compiling-native-addon-modules).

If using ARM64 Node.js on Windows 10 ARM, you must add "Visual C++ compilers and libraries for ARM64" and "Visual C++ ATL for ARM64".

</TabItem>
</Tabs>

### Install via npm

<Tabs defaultValue="install_native">
<TabItem value="install_native" label="Install native connector">

```bash
npm install @tdengine/client
```

</TabItem>
<TabItem value="install_rest" label="Install REST connector">

```bash
npm install @tdengine/rest
```

</TabItem>
</Tabs>

### Verify

After installing the TDengine client, use the `nodejsChecker.js` program to verify that the current environment supports Node.js access to TDengine.

Verification in details:

- Create an installation test folder such as `~/tdengine-test`. Download the [nodejsChecker.js source code](https://github.com/taosdata/taos-connector-node/blob/3.0/nodejs/examples/nodejsChecker.js) to your local machine.

- Execute the following command from the command-line.

```bash
npm init -y
npm install @tdengine/client
node nodejsChecker.js host=localhost
```

- After executing the above steps, the command-line will output the result of `nodejsChecker.js` connecting to the TDengine instance and performing a simple insert and query.

## Establishing a connection

Please choose to use one of the connectors.

<Tabs defaultValue="native">
<TabItem value="native" label="native connection">

Install and import the `@tdengine/client` package.

```javascript
//A cursor also needs to be initialized in order to interact with TDengine from Node.js.
const taos = require("@tdengine/client");
var conn = taos.connect({
  host: "127.0.0.1",
  user: "root",
  password: "taosdata",
  config: "/etc/taos",
  port: 0,
});
var cursor = conn.cursor(); // Initializing a new cursor

//Close a connection
conn.close();
```

</TabItem>
<TabItem value="rest" label="REST connection">

Install and import the `@tdengine/rest` package.

```javascript
//A cursor also needs to be initialized in order to interact with TDengine from Node.js.
import { options, connect } from "@tdengine/rest";
options.path = "/rest/sql";
// set host
options.host = "localhost";
// set other options like user/passwd

let conn = connect(options);
let cursor = conn.cursor();
```

</TabItem>
</Tabs>

## Usage examples

### Write data

#### SQL Write

<NodeInsert />

#### InfluxDB line protocol write

<NodeInfluxLine />

#### OpenTSDB Telnet line protocol write

<NodeOpenTSDBTelnet />

#### OpenTSDB JSON line protocol write

<NodeOpenTSDBJson />

### Querying data

<NodeQuery />


## More sample programs

| Sample Programs | Sample Program Description |
| --------------------------------------------------------------------------------------------------------------------------------- --------- | -------------------------------------- |
| [basicUse](https://github.com/taosdata/taos-connector-node/blob/3.0/nodejs/examples/queryExample.js)                                  | Basic operations such as establishing connections and running SQl commands.                       |
| [stmtBindBatch](https://github.com/taosdata/taos-connector-node/blob/3.0/nodejs/examples/bindParamBatch.js)                  | Binding multi-line parameter insertion.               | |
| [stmtBindSingleParamBatch](https://github.com/taosdata/taos-connector-node/blob/3.0/nodejs/examples/bindSingleParamBatch.js) | Columnar binding parameter insertion               |
| [stmtQuery](https://github.com/taosdata/taos-connector-node/blob/3.0/nodejs/examples/stmtQuery.js)                       | Binding parameter query                   |
| [schemless insert](https://github.com/taosdata/taos-connector-node/blob/3.0/nodejs/examples/schemaless.js)                   | Schemaless insert                 |
| [TMQ](https://github.com/taosdata/taos-connector-node/blob/3.0/nodejs/examples/tmq.js)                                 | Using data subscription                       |
| [asyncQuery](https://github.com/taosdata/taos-connector-node/blob/3.0/nodejs/examples/asyncQueryExample.js)                                         | Using asynchronous queries                   |
| [REST](https://github.com/taosdata/taos-connector-node/blob/3.0/typescript-rest/example/example.ts)                                    | Using TypeScript with the REST connector |

## Usage limitations

`@tdengine/client` 3.0.0 supports Node.js LTS v12.8.0 to 12.9.1 and 10.9.0 to 10.20.0.





## Frequently Asked Questions

1. Using REST connections requires starting taosadapter.

   ```bash
   sudo systemctl start taosadapter
   ```

2. Node.js versions

   `@tdengine/client` supports Node.js v10.9.0 to 10.20.0 and 12.8.0 to 12.9.1.

3. "Unable to establish connection", "Unable to resolve FQDN"

  Usually, the root cause is an incorrect FQDN configuration. You can refer to this section in the [FAQ](https://docs.tdengine.com/2.4/train-faq/faq/#2-how-to-handle-unable-to-establish-connection) to troubleshoot.

## Important update records

### Native connectors

| package name     | version | TDengine version    | Description                                                             |
|------------------|---------|---------------------|------------------------------------------------------------------|
| @tdengine/client | 3.0.0   | 3.0.0               | Supports TDengine 3.0. Not compatible with TDengine 2.x.                                                          |
| td2.0-connector  | 2.0.12  | 2.4.x；2.5.x；2.6.x | Fixed cursor.close() bug.                                 |
| td2.0-connector  | 2.0.11  | 2.4.x；2.5.x；2.6.x | Supports parameter binding, JSON tags and schemaless interface                  |
| td2.0-connector  | 2.0.10  | 2.4.x；2.5.x；2.6.x | Supports connection management, standard queries, connection queries, system information, and data subscription |
### REST Connector

| package name         | version | TDengine version    | Description                                                                      |
|----------------------|---------|---------------------|---------------------------------------------------------------------------|
| @tdengine/rest | 3.0.0   | 3.0.0               | Supports TDengine 3.0. Not compatible with TDengine 2.x.                                               |
| td2.0-rest-connector | 1.0.7   | 2.4.x；2.5.x；2.6.x | Removed default port 6041。                                                       |
| td2.0-rest-connector | 1.0.6   | 2.4.x；2.5.x；2.6.x | Fixed affectRows bug with create, insert, update, and alter. |
| td2.0-rest-connector | 1.0.5   | 2.4.x；2.5.x；2.6.x | Support cloud token                                                  |
| td2.0-rest-connector  | 1.0.3  | 2.4.x；2.5.x；2.6.x | Supports connection management, standard queries, system information, error information, and continuous queries          |

## API Reference

[API Reference](https://docs.taosdata.com/api/td2.0-connector/)