78 lines
2.0 KiB
Markdown
78 lines
2.0 KiB
Markdown
---
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title: experimental.unique() function
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description: >
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The `experimental.unique()` function returns all records containing unique
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values in the `_value` column.
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menu:
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flux_0_x_ref:
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name: experimental.unique
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parent: experimental
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weight: 302
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aliases:
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- /influxdb/v2.0/reference/flux/stdlib/experimental/unique/
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- /influxdb/cloud/reference/flux/stdlib/experimental/unique/
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related:
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- /flux/v0.x/stdlib/universe/unique/
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flux/v0.x/tags: [transformations, selectors]
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introduced: 0.112.0
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---
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The `experimental.unique()` function returns all records containing unique
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values in the `_value` column.
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`null` is considered a unique value.
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_`experimental.unique()` is a [selector function](/flux/v0.x/function-types/#selectors)._
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```js
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import "experimental"
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experimental.unique()
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```
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#### Output schema
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`experimental.unique()` outputs a single table for each input table and does
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the following:
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- Outputs a single record for each unique value.
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- Leaves group keys, columns, and values **unmodified**.
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{{% warn %}}
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#### Empty tables
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`experimental.unique()` drops empty tables.
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{{% /warn %}}
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## Parameters
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### tables {data-type="stream of tables"}
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Input data.
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Default is piped-forward data (`<-`).
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## Examples
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```js
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import "experimental"
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data
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|> experimental.unique()
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```
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{{< flex >}}
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{{% flex-content %}}
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##### Input data
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| _time | _field | _value |
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|:----- |:------ | ------:|
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| 2021-01-01T00:00:00Z | ver | v1 |
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| 2021-01-01T00:01:00Z | ver | v1 |
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| 2021-01-01T00:02:00Z | ver | v2 |
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| 2021-01-01T00:03:00Z | ver | |
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| 2021-01-01T00:04:00Z | ver | v3 |
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| 2021-01-01T00:05:00Z | ver | v3 |
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{{% /flex-content %}}
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{{% flex-content %}}
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##### Output data
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| _time | _field | _value |
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|:----- |:------ | ------:|
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| 2021-01-01T00:00:00Z | ver | v1 |
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| 2021-01-01T00:02:00Z | ver | v2 |
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| 2021-01-01T00:03:00Z | ver | |
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| 2021-01-01T00:04:00Z | ver | v3 |
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{{% /flex-content %}}
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{{< /flex >}} |