---
title: experimental.first() function
description: experimental.first() returns the first record with a non-null value in the _value column for each input table.
url: https://docs.influxdata.com/flux/v0/stdlib/experimental/first/
estimated_tokens: 1211
product: Flux
version: v0
---

# experimental.first() function

-   Flux 0.112.0+
-   View InfluxDB support

`experimental.first()` is [subject to change at any time](/flux/v0/stdlib/experimental/#experimental-packages-are-subject-to-change).

`experimental.first()` returns the first record with a non-null value in the `_value` column for each input table.

`experimental.first()` drops empty tables.

##### Function type signature

```js
(<-tables: stream[{A with _value: B}]) => stream[{A with _value: B}]
```

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

## Parameters

### tables

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

## Examples

### Return the first non-null value in each input table

```js
import "experimental"
import "sampledata"

sampledata.int(includeNull: true)
    |> experimental.first()
```

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

View example input and output

#### Input data

| _time | _value | *tag |
| --- | --- | --- |
| 2021-01-01T00:00:00Z | -2 | t1 |
| 2021-01-01T00:00:10Z |  | t1 |
| 2021-01-01T00:00:20Z | 7 | t1 |
| 2021-01-01T00:00:30Z |  | t1 |
| 2021-01-01T00:00:40Z |  | t1 |
| 2021-01-01T00:00:50Z | 4 | t1 |

| _time | _value | *tag |
| --- | --- | --- |
| 2021-01-01T00:00:00Z |  | t2 |
| 2021-01-01T00:00:10Z | 4 | t2 |
| 2021-01-01T00:00:20Z | -3 | t2 |
| 2021-01-01T00:00:30Z | 19 | t2 |
| 2021-01-01T00:00:40Z |  | t2 |
| 2021-01-01T00:00:50Z | 1 | t2 |

#### Output data

| _time | _value | *tag |
| --- | --- | --- |
| 2021-01-01T00:00:00Z | -2 | t1 |

| _time | _value | *tag |
| --- | --- | --- |
| 2021-01-01T00:00:10Z | 4 | t2 |

#### Related

-   [Query first and last values](/influxdb/v2/query-data/flux/first-last/)
-   [first() function](/flux/v0/stdlib/universe/first/)
-   [InfluxQL – FIRST()](/influxdb/v1/query_language/functions/#first)

[transformations](/flux/v0/tags/transformations/) [selectors](/flux/v0/tags/selectors/)