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
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.
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.