Name

regexp_match — returns a substring matching the regular expression to the supplied string

Synopsis

varchar regexp_match ( in pattern any ,
  inout str any ,
  in change_the_str integer );
 

Description

The regexp_match function returns a copy of substring of string str which matches the regular expression pattern.

Previous behavior of this function would cut the first characters of str until the end of regular expression matched substring. In this way str could be passed to this function again to find the next occurrence of substring that matches the regular expression. By default this behavior is not adopted by this function, but can be enabled for pre 3.2 compatibility by supplying the optional third parameter.

If either the pattern or str parameter contain wide characters this function will operate in wide mode, first converting any narrow characters to wide and returning a wide character response. Otherwise this function operates in narrow mode by default.

Parameters

pattern

The regular expression to match.

str

The string to be searched. In compatibility mode (change_the_str =1) this string in modified, removing the matched substring.

change_the_str

This new parameter allows this function to operate in pre 3.2 compatibility mode which modified the original string. By default this parameter is set to "0" so that the original string is never altered.

Returns

This function returns the a substring matching the regular expression.

Examples

Example 24.251. Examples

CREATE PROCEDURE all_tokens(IN pattern VARCHAR, IN str VARCHAR)
{
        DECLARE wrd VARCHAR;
        DECLARE ans VARCHAR;
        DECLARE str_i VARCHAR;

        ans:='';
        str_i := str;
        wrd := regexp_match(pattern,str_i);
        WHILE (wrd IS NOT NULL)
        {
                ans := concat(ans,',',wrd);
                wrd := regexp_match(pattern, str_i, 1);
        };
        RETURN ans;
};


[Note] Compatibility:

The regular expressions supported here follow version 7.9 of the Perl Compatible Regular Expression (PCRE) syntax.