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.

drop(columns: ["col1", "col2"])

// OR

drop(fn: (column) => column =~ /usage*/)

Parameters

columns

Columns to removed 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

The following examples use data provided by the sampledata package to show how drop() transforms data.

• Drop a list of columns
• Drop columns matching a predicate

Drop a list of columns

import "sampledata"

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

Drop columns matching a predicate

import "sampledata"

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