elasticsearch/docs/reference/esql/functions/count.asciidoc
Abdon Pijpelink 980bc500b0
[DOCS] Support for nested functions in ES|QL STATS...BY (#104788)
* Document nested expressions for stats

* More docs

* Apply suggestions from review

- count-distinct.asciidoc
  - Content restructured, moving the section about approximate counts to end of doc.

- count.asciidoc
  - Clarified that omitting the `expression` parameter in `COUNT` is equivalent to `COUNT(*)`, which counts the number of rows.

- percentile.asciidoc
  - Moved the note about `PERCENTILE` being approximate and non-deterministic to end of doc.

- stats.asciidoc
  - Clarified the `STATS` command
  -  Added a note indicating that individual `null` values are skipped during aggregation

* Comment out mentioning a buggy behavior

* Update sum with inline function example, update test file

* Fix typo

* Delete line

* Simplify wording

* Fix conflict fix typo

---------

Co-authored-by: Liam Thompson <leemthompo@gmail.com>
Co-authored-by: Liam Thompson <32779855+leemthompo@users.noreply.github.com>
2024-01-30 19:29:12 +01:00

58 lines
1.2 KiB
Text

[discrete]
[[esql-agg-count]]
=== `COUNT`
*Syntax*
[source,esql]
----
COUNT([expression])
----
*Parameters*
`expression`::
Expression that outputs values to be counted.
If omitted, equivalent to `COUNT(*)` (the number of rows).
*Description*
Returns the total number (count) of input values.
*Supported types*
Can take any field type as input.
*Examples*
[source.merge.styled,esql]
----
include::{esql-specs}/stats.csv-spec[tag=count]
----
[%header.monospaced.styled,format=dsv,separator=|]
|===
include::{esql-specs}/stats.csv-spec[tag=count-result]
|===
To count the number of rows, use `COUNT()` or `COUNT(*)`:
[source.merge.styled,esql]
----
include::{esql-specs}/docs.csv-spec[tag=countAll]
----
[%header.monospaced.styled,format=dsv,separator=|]
|===
include::{esql-specs}/docs.csv-spec[tag=countAll-result]
|===
The expression can use inline functions. This example splits a string into
multiple values using the `SPLIT` function and counts the values:
[source.merge.styled,esql]
----
include::{esql-specs}/stats.csv-spec[tag=docsCountWithExpression]
----
[%header.monospaced.styled,format=dsv,separator=|]
|===
include::{esql-specs}/stats.csv-spec[tag=docsCountWithExpression-result]
|===