REGEXP_INSTR

The REGEXP_INSTR function searches a string for a substring with a specified pattern and returns the position of that substring.

The function evaluates strings using characters as defined by the input character set.

Return Value

When the pattern is found a NUMBER; otherwise 0.

Syntax

REGEXP_INSTR (source_char, pattern[, position[, occurrence[, return_option[, match_parameter ]]]])

Parameters

source_char

The text expression for which the function searches.

pattern

The text expression for which the function searches. It is usually a text literal and can contain up to 512 bytes. The function interprets a period as a wildcard character that matches any character.

position

A nonzero integer indicating the character of source_char where the function begins the search. When position is negative, then the function counts and searches backward from the end of string. The default value of position is 1, which means that the function begins searching at the first character of source_char.

occurrence

An integer indicating which occurrence of pattern the function should search for. The value of occurrence must be positive. The default values of occurrence is 1, meaning the function searches for the first occurrence of pattern.

return_option

Specify 0 (zero) when you want the function to return the position of the first matched character (default), or 1 when you want the function to return the position of the character following the match.

match_parameter

A text expression that lets you change the default matching behavior of the function. You can specify one or more of the values shown in the following table.

Value	Specifies
c	Case-sensitive matching.
i	Case-insensitive matching.
m	Treat the source string as multiple lines. The function interprets ^ (caret) and $ (dollar sign) as the start and end, respectively, of any line anywhere in the source string, rather than only at the start or end of the entire source string. By default, the function treats the source string as a single line.
n	A newline character is among the characters matched by a period (the wildcard character). By default, it is not.
x	Ignores whitespace characters.

Examples

The following statement

REGEXP_INSTR('Mississippi', 'i', 1, 3) 

searches the string Mississippi for the third instance of the letter i, beginning the search at the first letter. It returns the value 8.