---
title: distinct() function
description: >
  `distinct()` returns all unique values in a specified column.
menu:
  flux_v0_ref:
    name: distinct
    parent: universe
    identifier: universe/distinct
weight: 101
flux/v0/tags: [transformations, selectors]
introduced: 0.7.0
---

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`distinct()` returns all unique values in a specified column.

The `_value` of each output record is set to a distinct value in the specified column.
`null` is considered its own distinct value if present.

##### Function type signature

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

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

## Parameters

### column

Column to return unique values from. Default is `_value`.



### tables

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




## Examples

- [Return distinct values from the _value column](#return-distinct-values-from-the-_value-column)
- [Return distinct values from a non-default column](#return-distinct-values-from-a-non-default-column)
- [Return distinct values from data with null values](#return-distinct-values-from-data-with-null-values)

### Return distinct values from the _value column

```js
import "sampledata"

sampledata.int()
    |> distinct()

```

{{< expand-wrapper >}}
{{% 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

| *tag | _value  |
| ---- | ------- |
| t1   | -2      |
| t1   | 10      |
| t1   | 7       |
| t1   | 17      |
| t1   | 15      |
| t1   | 4       |

| *tag | _value  |
| ---- | ------- |
| t2   | 19      |
| t2   | 4       |
| t2   | -3      |
| t2   | 13      |
| t2   | 1       |

{{% /expand %}}
{{< /expand-wrapper >}}

### Return distinct values from a non-default column

```js
import "sampledata"

sampledata.int()
    |> distinct(column: "tag")

```

{{< expand-wrapper >}}
{{% 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

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

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

{{% /expand %}}
{{< /expand-wrapper >}}

### Return distinct values from data with null values

```js
import "sampledata"

sampledata.int(includeNull: true)
    |> distinct()

```

{{< expand-wrapper >}}
{{% expand "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

| *tag | _value  |
| ---- | ------- |
| t1   | -2      |
| t1   |         |
| t1   | 7       |
| t1   | 4       |

| *tag | _value  |
| ---- | ------- |
| t2   |         |
| t2   | 4       |
| t2   | -3      |
| t2   | 19      |
| t2   | 1       |

{{% /expand %}}
{{< /expand-wrapper >}}