---
title: drop() function
description: drop() removes specified columns from a table.
url: https://docs.influxdata.com/flux/v0/stdlib/universe/drop/
estimated_tokens: 2052
product: Flux
version: v0
---

# drop() function

-   Flux 0.7.0+
-   View InfluxDB support

`drop()` removes specified columns from a table.

Columns are specified either through a list or a predicate function. When a dropped column is part of the group key, it is removed from the key. If a specified column is not present in a table, the function returns an error.

##### Function type signature

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

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

## Parameters

### columns

List of columns to remove from input tables. Mutually exclusive with `fn`.

### fn

Predicate function with a `column` parameter that returns a boolean value indicating whether or not the column should be removed from input tables. Mutually exclusive with `columns`.

### tables

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

## Examples

-   [Drop a list of columns](#drop-a-list-of-columns)
-   [Drop columns matching a predicate](#drop-columns-matching-a-predicate)

### Drop a list of columns

```js
import "sampledata"

sampledata.int()
    |> drop(columns: ["_time", "tag"])
```

[](#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 | 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

| _value |
| --- |
| -2 |
| 10 |
| 7 |
| 17 |
| 15 |
| 4 |
| 19 |
| 4 |
| -3 |
| 19 |
| 13 |
| 1 |

### Drop columns matching a predicate

```js
import "sampledata"

sampledata.int()
    |> drop(fn: (column) => column =~ /^t/)
```

[](#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 | 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 |
| --- | --- |
| 2021-01-01T00:00:00Z | -2 |
| 2021-01-01T00:00:10Z | 10 |
| 2021-01-01T00:00:20Z | 7 |
| 2021-01-01T00:00:30Z | 17 |
| 2021-01-01T00:00:40Z | 15 |
| 2021-01-01T00:00:50Z | 4 |
| 2021-01-01T00:00:00Z | 19 |
| 2021-01-01T00:00:10Z | 4 |
| 2021-01-01T00:00:20Z | -3 |
| 2021-01-01T00:00:30Z | 19 |
| 2021-01-01T00:00:40Z | 13 |
| 2021-01-01T00:00:50Z | 1 |

#### Related

-   [keep() function](/flux/v0/stdlib/universe/keep/)

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