Regular Expression Functions : Introduction « Regular Expressions Functions « Oracle PL/SQL Tutorial

1. Oracle PL/SQL Tutorial
2. Regular Expressions Functions
3. Introduction

The regular expression functions available in Oracle Database 10g.

REGEXP_LIKE(x, pattern [, match_option])

Returns true when the source x matches the regular expression pattern.

You can change the default matching using match_option, which may be set to:

1. 'c', which specifies case sensitive matching (default).
2. 'i', which specifies case insensitive matching.
3. 'n', which allows you to use the match-any-character operator.
4. 'm', which treats x as multiple line.

REGEXP_INSTR(x, pattern [, start [, occurrence [, return_option [, match_option]]]])

Searches for pattern in x and returns the position at which pattern occurs.

You can supply an optional:

1. start position to begin the search.
2. occurrence that indicates which occurrence of pattern_exp should be returned.
3. return_option that indicates what integer to return. 0 specifies the integer to return is the position of the first character in x; non-zero specifies the integer to return is the position of the character in x after the occurrence.
4. match_option to change the default matching.

REGEXP_REPLACE(x, pattern [, replace_string [, start [, occurrence [, match_option]]]])

Searches x for pattern and replaces it with replace_string.

The other options have the same meaning as those shown earlier.

REGEXP_SUBSTR(x, pattern [, start [, occurrence [, match_option]]])

Returns a substring of x that matches pattern, which begins at the position specified by start.

The other options have the same meaning as those shown earlier.

Quote from:

Oracle Database 10g SQL (Osborne ORACLE Press Series) (Paperback)

# Paperback: 608 pages

# Publisher: McGraw-Hill Osborne Media; 1st edition (February 20, 2004)

# Language: English

# ISBN-10: 0072229810

# ISBN-13: 978-0072229813