countby

Description

The countby command generates a count for each distinct value in a given expression, effectively grouping the results by that key.

note

Unlike count, which tallies all records in a set, countby provides a per-group count based on the specified key or expression.

Syntax

countby <expression> [as <alias>] [into <keypath>] [(asc|desc)]

Example

Use case: Count requests by HTTP status code

When analyzing logs, it's often useful to understand the distribution of response types. The countby command groups documents by status_code and counts the number of requests in each group.

Example data

{ "status_code": 200, "path": "/home" },
{ "status_code": 200, "path": "/about" },
{ "status_code": 404, "path": "/missing" },
{ "status_code": 500, "path": "/checkout" }

Example query

countby status_code into request_count asc

Example output

status_code	request_count
404	1
500	1
200	2

The countby command produces one record per unique status code, with a count of how many times each appears. Using asc orders the results from the smallest count to the largest.