drop() function

The drop() function 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 will be removed from the key. If a specified column is not present in a table, it will return an error.

*Function type: Transformation
**Output data type:* Record

drop(columns: ["col1", "col2"])
// OR
drop(fn: (column) => column =~ /usage*/)

Parameters

Make sure fn parameter names match each specified parameter. To learn why, see Match parameter names.

columns

Columns to be removed from the table. Cannot be used with fn.

*Data type: Array of strings*

fn

A predicate function which takes a column name as a parameter (column) and returns a boolean indicating whether or not the column should be removed from the table. Cannot be used with columns.

*Data type: Function*

Examples

Drop a list of columns

from(bucket: "example-bucket")
    |> range(start: -5m)
    |> drop(columns: ["host", "_measurement"])

Drop columns matching a predicate

from(bucket: "example-bucket")
  |> range(start: -5m)
  |> drop(fn: (column) => column =~ /usage*/)