elasticsearch/docs/reference/esql/functions/parameters/substring.asciidoc

// This is generated by ESQL's AbstractFunctionTestCase. Do no edit it. See ../README.md for how to regenerate it.

*Parameters*

`string`::
String expression. If `null`, the function returns `null`.

`start`::
Start position.

`length`::
Length of the substring from the start position. Optional; if omitted, all positions after `start` are returned.