Oracle Regular Expressions Pocket Reference

Name

\ (Backslash) — Escapes a metacharacter

Synopsis

Use the backslash (\) to treat as normal a character that would otherwise have a special meaning. For example, to extract a dollar amount from a sentence, you might escape the period (.) and the dollar sign ($) as follows:

SELECT REGEXP_SUBSTR(
   'This book costs $9.95 in the U.S.',
   '\$[[:digit:]]+\.[[:digit:]]+')
FROM dual;

$9.95

The \$ in this expression requires that the matching text begin with a dollar sign. The \. requires a period between the two digit groups.

To specify a backslash in an expression, escape it with another backslash. The following query retrieves all text up to and including the last backslash:

SELECT REGEXP_SUBSTR(
   'I want this \ but not this',
   '.*\\')
FROM dual;

I want this \

If the character following a backslash in an expression is not a metacharacter, then the backslash is ignored:

SELECT REGEXP_SUBSTR('\test','\test')
FROM dual;

test

The \ has no special meaning within square brackets ([]). When used within square brackets, \ represents itself.