distinct_count

Description

Returns the number of distinct, non-null values for a given expression.

• Each unique value is counted once per group.

note

distinct_count is an aggregation function and must be used with a grouping keyword such as groupby.

Syntax

distinct_count(expression: any): number

Arguments

Name	Type	Required	Description
expression	any	true	Expression whose unique, non-null values are counted

Example

Use case: Count active users per application

Suppose you want to know how many unique users have been active in a given timeframe.

Example data

{ "applicationname": "checkout-service", "username": "alice" },
{ "applicationname": "checkout-service", "username": "bob" },
{ "applicationname": "checkout-service", "username": "alice" }

Example query

groupby $l.applicationname aggregate distinct_count($d.username) as active_users

Example output

applicationname	active_users
checkout-service	2