docs-v2/content/influxdb/v2.1/api-guide/client-libraries/nodejs/query.md

title	description	menu	influxdb/v2.1/tags	weight	aliases
Query data with the InfluxDB JavaScript client library	Use the JavaScript client library to query data with the InfluxDB API in Node.js.	influxdb_2_1 name parent Query Node.js	client libraries JavaScript	201	/influxdb/v2.1/reference/api/client-libraries/nodejs/query

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 from an observable table.

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. {{% warn %}} To prevent SQL injection attacks, avoid concatenating unsafe user input with queries. {{% /warn %}}

   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 queryRows() method of the query client to query InfluxDB. queryRows() takes a Flux query and an RxJS Observer object. The client returns [table](/{{% latest "influxdb" %}}/reference/syntax/annotated-csv/#tables) metadata and rows as an RxJS Observable. queryRows() subscribes your observer to the observable. Finally, the observer logs the rows from the response to the terminal.

   const observer = {
     next(row, tableMeta) {
       const o = tableMeta.toObject(row)
       console.log(
         `${o._time} ${o._measurement} in '${o.location}' (${o.sensor_id}): ${o._field}=${o._value}`
       )
     }
   }
   
   queryApi.queryRows(fluxQuery, observer)
   
   

Complete example

{{% get-shared-text "api/v2.0/query/query.mjs" %}}

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

{{% api/v2dot0/nodejs/learn-more %}}