node.mdx

---
toc_max_heading_level: 4
sidebar_position: 6
sidebar_label: Node.js
title: TDengine Node.js Connector
---

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

import Preparation from "./_preparation.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";
import NodeAsyncQuery from "../../07-develop/04-query-data/_js_async.mdx";

`td2.0-connector` and `td2.0-rest-connector` are the official Node.js language connectors for TDengine. Node.js developers can develop applications to access TDengine instance data.

`td2.0-connector` is a **native connector** that connects to TDengine instances via the TDengine client driver (taosc) and supports data writing, querying, subscriptions, schemaless writing, and bind interface. The `td2.0-rest-connector` is a **REST connector** that 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 Node.js connector source code is hosted on [GitHub](https://github.com/taosdata/taos-connector-node).

## 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 function
6. Schemaless

### REST Connector

1. connection management
2. general queries
3. Continuous query

## Installation steps

### Pre-installation

- 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)
- `td2.0-connector` 2.0.6 supports Node.js LTS v10.9.0 or later, Node.js LTS v12.8.0 or later; 2.0.5 and earlier support Node.js LTS v10.x versions. Other versions may have package compatibility issues
- `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 td2.0-connector
```

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

```bash
npm i td2.0-rest-connector
```

</TabItem>
</Tabs>

### Installation verification

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 a new installation verification directory, e.g. `~/tdengine-test`, and download the [nodejsChecker.js source code](https://github.com/taosdata/TDengine/tree/develop/examples/nodejs/) from GitHub. to the work directory.

- Execute the following command from the command-line.

```bash
npm init -y
npm install td2.0-connector
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 refer to `td2.0-connector` package:

```javascript
//A cursor also needs to be initialized in order to interact with TDengine from Node.js.
const taos = require("td2.0-connector");
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 refer to `td2.0-rest-connector`package:

```javascript
//A cursor also needs to be initialized in order to interact with TDengine from Node.js.
import { options, connect } from "td2.0-rest-connector";
options.path = "/rest/sqlt";
// 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 Writing

<NodeInsert />

#### InfluxDB line protocol writing

<NodeInfluxLine />

#### OpenTSDB Telnet line protocol writing

<NodeOpenTSDBTelnet />

#### OpenTSDB JSON line protocol writing

<NodeOpenTSDBJson />

### Query data

#### Synchronous queries

<NodeQuery />

#### asynchronous query

<NodeAsyncQuery />

## More Sample Programs

| Sample Programs | Sample Program Description |
| --------------------------------------------------------------------------------------------------------------------------------- --------- | -------------------------------------- |
| [connection](https://github.com/taosdata/taos-connector-node/tree/develop/nodejs/examples/cursorClose.js) | Example of establishing a connection.                       |
| [stmtBindBatch](https://github.com/taosdata/taos-connector-node/tree/develop/nodejs/examples/stmtBindParamBatchSample.js) | Example of binding a multi-line parameter Example of inserting.               |
| [stmtBind](https://github.com/taosdata/taos-connector-node/tree/develop/nodejs/examples/stmtBindParamSample.js) | Example of a line-by-line bind parameter insertion.           |
| [stmtBindSingleParamBatch](https://github.com/taosdata/taos-connector-node/tree/develop/nodejs/examples/) stmtBindSingleParamBatchSample.js) | Example of binding parameters by column.               |
| [stmtUseResult](https://github.com/taosdata/taos-connector-node/tree/develop/nodejs/examples/stmtUseResultSample.js) | Example of a bound parameter query.                   |
| [json tag](https://github.com/taosdata/taos-connector-node/tree/develop/nodejs/examples/testJsonTag.js) | Example of using Json tag.                  |
| [Nanosecond](https://github.com/taosdata/taos-connector-node/tree/develop/nodejs/examples/testNanoseconds.js) | An example of using timestamps with nanosecond precision.         |
| [Microsecond](https://github.com/taosdata/taos-connector-node/tree/develop/nodejs/examples/testMicroseconds.js) | Example of using microsecond timestamp.         |
| [schemless insert](https://github.com/taosdata/taos-connector-node/tree/develop/nodejs/examples/testSchemalessInsert.js) | schemless Example of a schemless insert.                 |
| [subscribe](https://github.com/taosdata/taos-connector-node/tree/develop/nodejs/examples/testSubscribe.js) | Example of using subscribe.                       |
| [asyncQuery](https://github.com/taosdata/taos-connector-node/tree/develop/nodejs/examples/tset.js) | An example of using asynchronous queries.                   |
| [REST](https://github.com/taosdata/taos-connector-node/blob/develop/typescript-rest/example/example.ts) | An example of using TypeScript with REST connections. |

## Usage restrictions

Node.js Connector >= v2.0.6 currently supports node versions >=v12.8.0 <= v12.9.1 || >=v10.20.0 <= v10.9.0; v10.x versions are supported in 2.0.5 and earlier, other versions may have package compatibility issues.

## Other notes

See [video tutorial](https://www.taosdata.com/blog/2020/11/11/1957.html) for the Node.js connector usage.

## Frequently Asked Questions

1. Using REST connections requires starting taosadapter.

   ```bash
   sudo systemctl start taosadapter
   ```

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

  Usually, root cause is the FQDN is not configured correctly. You can refer to [How to understand TDengine's FQDN (In Chinese)](https://www.taosdata.com/blog/2021/07/29/2741.html).

## Important Updates

### Native connectors

| td2.0-connector version | description |
| -------------------- | ---------------------------------------------------------------- |
| 2.0.12 | Fix bug with cursor.close() error. | 2.0.12 | Fix bug with cursor.close() error.
| 2.0.11 | Support for binding parameters, json tag, schemaless interface, etc.                  |
| 2.0.10 | Support connection management, general query, continuous query, get system information, subscribe function, etc. | ### REST Connector

### REST Connector

| td2.0-rest-connector version | Description |
| ------------------------- | ---------------------------------------------------------------- |
| 1.0.3 | Support connection management, general query, get system information, error message, continuous query, etc. |# API Reference

## API Reference

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