A function using the LIKE operator to return a phone number's area code
SQL> SQL> -- A function using the LIKE operator to return a phone number's area code. SQL> SQL> CREATE OR REPLACE FUNCTION area_code (phone_number IN VARCHAR2) 2 RETURN VARCHAR2 AS 3 BEGIN 4 IF phone_number LIKE '___-___-____' THEN 5 6 RETURN SUBSTR(phone_number,1,3); 7 ELSE 8 --there is no area code 9 RETURN 'none'; 10 END IF; 11 END; 12 / Function created. SQL> SQL> SQL> select area_code('123456789') from dual; AREA_CODE('123456789') -------------------------------------------------------------------------------- none SQL> SQL> SQL> select area_code('123-456-7890') from dual;