---
title: set() function
description: >
  `set()` assigns a static column value to each row in the input tables.
menu:
  flux_v0_ref:
    name: set
    parent: universe
    identifier: universe/set
weight: 101
flux/v0/tags: [transformations]
introduced: 0.7.0
---

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`set()` assigns a static column value to each row in the input tables.

`set()` may modify an existing column or add a new column.
If the modified column is part of the group key, output tables are regrouped as needed.
`set()` can only set string values.

##### Function type signature

```js
(<-tables: stream[A], key: string, value: string) => stream[A] where A: Record
```

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

## Parameters

### key
({{< req >}})
Label of the column to modify or set.



### value
({{< req >}})
String value to set.



### tables

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




## Examples

### Set a column to a specific string value

```js
import "sampledata"

sampledata.int()
    |> set(key: "host", value: "prod1")

```

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{{% expand "View example input and output" %}}

#### Input data

| _time                | _value  | *tag |
| -------------------- | ------- | ---- |
| 2021-01-01T00:00:00Z | -2      | t1   |
| 2021-01-01T00:00:10Z | 10      | t1   |
| 2021-01-01T00:00:20Z | 7       | t1   |
| 2021-01-01T00:00:30Z | 17      | t1   |
| 2021-01-01T00:00:40Z | 15      | t1   |
| 2021-01-01T00:00:50Z | 4       | t1   |

| _time                | _value  | *tag |
| -------------------- | ------- | ---- |
| 2021-01-01T00:00:00Z | 19      | 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 | 13      | t2   |
| 2021-01-01T00:00:50Z | 1       | t2   |


#### Output data

| _time                | _value  | *tag | host  |
| -------------------- | ------- | ---- | ----- |
| 2021-01-01T00:00:00Z | -2      | t1   | prod1 |
| 2021-01-01T00:00:10Z | 10      | t1   | prod1 |
| 2021-01-01T00:00:20Z | 7       | t1   | prod1 |
| 2021-01-01T00:00:30Z | 17      | t1   | prod1 |
| 2021-01-01T00:00:40Z | 15      | t1   | prod1 |
| 2021-01-01T00:00:50Z | 4       | t1   | prod1 |

| _time                | _value  | *tag | host  |
| -------------------- | ------- | ---- | ----- |
| 2021-01-01T00:00:00Z | 19      | t2   | prod1 |
| 2021-01-01T00:00:10Z | 4       | t2   | prod1 |
| 2021-01-01T00:00:20Z | -3      | t2   | prod1 |
| 2021-01-01T00:00:30Z | 19      | t2   | prod1 |
| 2021-01-01T00:00:40Z | 13      | t2   | prod1 |
| 2021-01-01T00:00:50Z | 1       | t2   | prod1 |

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