---
title: count() function
description: count() returns the number of records in each input table.
url: https://docs.influxdata.com/flux/v0/stdlib/universe/count/
estimated_tokens: 730
product: Flux
version: v0
publisher: InfluxData
canonical: https://docs.influxdata.com/flux/v0/stdlib/universe/count/
date: '2024-04-08T16:01:02-06:00'
lastmod: '2024-04-08T16:01:02-06:00'
---

* Flux 0.7.0+

InfluxDB support

`count()` returns the number of records in each input table.

The function counts both null and non-null records.

#### 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`|

##### Function type signature

```js
(<-tables: stream[A], ?column: string) => stream[B] where A: Record, B: Record
```

For more information, see [Function type signatures](/flux/v0/function-type-signatures/).

## Parameters

### column

Column to count values in and store the total count.

### tables

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

## Examples

* [Count the number of records in each input table](#count-the-number-of-records-in-each-input-table)
* [Count the number of records with a specific value](#count-the-number-of-records-with-a-specific-value)

### Count the number of records in each input table

```js
import "sampledata"

sampledata.string()
    |> count()
```

### Count the number of records with a specific value

1. Use `filter()` to filter data by the specific value you want to count.
2. Use `count()` to count the number of rows in the table.

```js
import "sampledata"

data =
    sampledata.int()
        |> filter(fn: (r) => r._value > 10)

data
    |> count()
```

[](#view-example-input-and-output)

View example input and output

#### Input data

|       \_time       |\_value|\*tag|
|--------------------|-------|-----|
|2021-01-01T00:00:30Z|  17   | t1  |
|2021-01-01T00:00:40Z|  15   | t1  |

|       \_time       |\_value|\*tag|
|--------------------|-------|-----|
|2021-01-01T00:00:00Z|  19   | t2  |
|2021-01-01T00:00:30Z|  19   | t2  |
|2021-01-01T00:00:40Z|  13   | t2  |

#### Output data

|\*tag|\_value|
|-----|-------|
| t1  |   2   |

|\*tag|\_value|
|-----|-------|
| t2  |   3   |

#### Related

* [InfluxQL – COUNT()](/influxdb/v1/query_language/functions/#count)
* [experimental.count() function](/flux/v0/stdlib/experimental/count/)

[transformations](/flux/v0/tags/transformations/)[aggregates](/flux/v0/tags/aggregates/)
| Function | Parameter |
| --- | --- |
| Function | Parameter |
| filter() | onEmpty: "keep" |
| window() | createEmpty: true |
| aggregateWindow() | createEmpty: true |

| _time | _value | *tag |
| --- | --- | --- |
| _time | _value | *tag |
| 2021-01-01T00:00:30Z | 17 | t1 |
| 2021-01-01T00:00:40Z | 15 | t1 |

| _time | _value | *tag |
| --- | --- | --- |
| _time | _value | *tag |
| 2021-01-01T00:00:00Z | 19 | t2 |
| 2021-01-01T00:00:30Z | 19 | t2 |
| 2021-01-01T00:00:40Z | 13 | t2 |

| *tag | _value |
| --- | --- |
| *tag | _value |
| t1 | 2 |

| *tag | _value |
| --- | --- |
| *tag | _value |
| t2 | 3 |