Query data with the InfluxDB JavaScript client library

Use the InfluxDB JavaScript client library in a Node.js environment to query InfluxDB.

The following example sends a Flux query to an InfluxDB bucket and outputs rows as asynchronous iterable.

Before you begin

• Install the client library and other dependencies.

Query InfluxDB

1. Change to your new project directory and create a file for your query module.

   cd influx-node-app && touch query.js
   

2. Instantiate an InfluxDB client. Provide your InfluxDB URL and API token. Use the getQueryApi() method of the client. Provide your InfluxDB organization ID to create a configured query client.

   import { InfluxDB, Point } from '@influxdata/influxdb-client'
   
   const queryApi = new InfluxDB({YOUR_URL, YOUR_API_TOKEN}).getQueryApi(YOUR_ORG)
   

   Replace the following:

   • YOUR_URL: InfluxDB URL
   • YOUR_API_TOKEN: InfluxDB API token
   • YOUR_ORG: InfluxDB organization ID

3. Create a Flux query for your InfluxDB bucket. Store the query as a string variable.

   To prevent SQL injection attacks, avoid concatenating unsafe user input with queries.

   const fluxQuery =
     'from(bucket: "YOUR_BUCKET")
       |> range(start: 0)
       |> filter(fn: (r) => r._measurement == "temperature")'
   

   Replace YOUR_BUCKET with the name of your InfluxDB bucket.

4. Use the iterateRows() method of the query client to query InfluxDB. iterateRows() takes a Flux query and returns table as an asynchronous collection. The client returns table metadata and rows as an as an AsyncIterable.

   const myQuery = async () => {
     for await (const {values, tableMeta} of queryApi.iterateRows(fluxQuery)) {
       const o = tableMeta.toObject(values)
       console.log(
         `${o._time} ${o._measurement} in '${o.location}' (${o.sensor_id}): ${o._field}=${o._value}`
       )
     }
   }
   myQuery()
   

Complete example

'use strict'
/** @module query 
 * Queries a data point in InfluxDB using the Javascript client library with Node.js.
**/

import { InfluxDB, Point } from '@influxdata/influxdb-client'

/** Environment variables **/
const url = process.env.INFLUX_URL || ''
const token = process.env.INFLUX_TOKEN
const org = process.env.INFLUX_ORG || ''

/**
 * Instantiate the InfluxDB client
 * with a configuration object.
 *
 * Get a query client configured for your org.
 **/
const queryApi = new InfluxDB({url, token}).getQueryApi(org)

/** To avoid SQL injection, use a string literal for the query. */
const fluxQuery = 'from(bucket:"air_sensor") |> range(start: 0) |> filter(fn: (r) => r._measurement == "temperature")'

const myQuery = async () => {
  for await (const {values, tableMeta} of queryApi.iterateRows(fluxQuery)) {
    const o = tableMeta.toObject(values)
    console.log(
      `${o._time} ${o._measurement} in '${o.location}' (${o.sensor_id}): ${o._field}=${o._value}`
    )
  }
}

/** Execute a query and receive line table metadata and rows. */
myQuery()

To run the example from a file, set your InfluxDB environment variables and use node to execute the JavaScript file.

export INFLUX_URL=http://localhost:8086 && \
export INFLUX_TOKEN=YOUR_API_TOKEN && \
export INFLUX_ORG=YOUR_ORG && \
node query.js

For more examples and information, see the JavaScript client on GitHub.