REGEXP_SUBSTR(x, pattern [, start [, occurrence [, match_option]]]) gets a substring of x that matches pattern, which begins at the position specified by start. : REGEXP_SUBSTR « Regular Expressions Functions « Oracle PL/SQL Tutorial





The following example returns the substring that matches the regular expression l[[:alpha:]] {4} using REGEXP_SUBSTR():

SQL>
SQL> SELECT REGEXP_SUBSTR('abcedfghijklumnoprstuvwxyzabcedfghijklumnoprstuvwxyzabcedfghijklumnoprstuvwxyz', 'l[[:alpha:]]{4}') AS result
  2  FROM dual;

RESUL
-----
lumno

SQL>
SQL>










18.5.REGEXP_SUBSTR
18.5.1.REGEXP_SUBSTR(x, pattern [, start [, occurrence [, match_option]]]) gets a substring of x that matches pattern, which begins at the position specified by start.
18.5.2.Regexp_Substr returns a string of data type VARCHAR2 or CLOB
18.5.3.Grouping
18.5.4.Group the letters 'ir' together by putting them in parentheses and then parenthesizing the suffix using alternation
18.5.5.Backreference
18.5.6.Search for (