docs-v2/content/flux/v0.x/stdlib/universe/count.md

title	description	aliases	menu	weight	flux/v0.x/tags	related	introduced
count() function	The `count()` function outputs the number of non-null records in a column.	/influxdb/v2.0/reference/flux/functions/transformations/aggregates/count /influxdb/v2.0/reference/flux/functions/built-in/transformations/aggregates/count/ /influxdb/v2.0/reference/flux/stdlib/built-in/transformations/aggregates/count/ /influxdb/cloud/reference/flux/stdlib/built-in/transformations/aggregates/count/	flux_0_x_ref name parent count universe	102	aggregates transformations	/{{< latest "influxdb" "v1" >}}/query_language/functions/#count, InfluxQL – COUNT() /flux/v0.x/stdlib/experimental/count/	0.7.0

The count() function outputs the number of records in a column. It counts both null and non-null records. count() is an aggregate function.

Output data type: Integer

count(column: "_value")

{{% note %}}

Empty tables

count() returns 0 for empty tables. To keep empty tables in your data, set the following parameters for the following functions:

Function	Parameter
filter()	onEmpty: "keep"
window()	createEmpty: true
aggregateWindow()	createEmpty: true
{{% /note %}}

Parameters

column

The column on which to operate. Defaults to "_value".

tables

Input data. Default is piped-forward data (<-).

Examples

{{% flux/sample-example-intro %}}

Count the number of rows in each input table

import "sampledata"

sampledata.string()
    |> count()

{{% expand "View input and output" %}} {{< flex >}} {{% flex-content %}}

Input data

{{% flux/sample "string" %}}

{{% /flex-content %}} {{% flex-content %}}

Output data

tag	_value
t1	6

tag	_value
t2	6

{{% /flex-content %}} {{< /flex >}} {{% /expand %}}