> ## Documentation Index
> Fetch the complete documentation index at: https://www.integrate.io/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# ETL: REGEX_EXTRACT

> Extract matching text from a string using a regular expression, returning the nth occurrence by index. Use for pattern-based parsing in ETL jobs.

## Description

Returns the nth occurrence (specified by index) of a string that matches the regular expression.

## Syntax

`REGEX_EXTRACT(string_expression, regex, index)`

## Arguments

*string\_expression* - string expression

*regex* - string expression indicating a regular expression

*index* - integer indicating the occurrence

## Examples

`REGEX_EXTRACT('213.131.343.135:5020', '(.*)\\:(.*)', 1)` returns '213.131.343.135'

## Notes

* The regex string must be enclosed by single quotes.
* If string matching fails, null is returned.
* Make sure to escape a single-quotes (i.e. \\' )
* Make sure to escape back-slashes that are part of a regular expression escape sequence (e.g. instead of \s as shorthand for whitespace, use \\\s )

## Return value datatype

String

## Impact of null value

If input is null, returns null.