Extending your options with regular expressions : CHAR VARCHAR2 Functions « PL SQL Data Types « Oracle PL/SQL Tutorial

Regular expressions cannot be used as parameters in the standard Oracle built-in text search functions: LIKE, SUBSTR, INSTR, and REPLACE.

Regular expressions have their own versions of the same functions: REGEXP_ LIKE, REGEXP_SUBSTR, REGEXP_INSTR, and REGEXP_REPLACE.

SQL> declare
  2      v1_tx VARCHAR2(2000):='*ABC*BBC*';
  3  begin
  4      DBMS_OUTPUT.put_line('First hit:'|| REGEXP_INSTR(V1_TX,'A|BBC',1,1));
  5      DBMS_OUTPUT.put_line('Second hit:'|| REGEXP_INSTR(V1_TX,'A|BBC',1,2));
  6  end;
  7  /
First hit:2
Second hit:6

PL/SQL procedure successfully completed.

SQL>

21.5.CHAR VARCHAR2 Functions
	21.5.1.	Useful character built-in functions
	21.5.2.	Compare char type value with blank space
	21.5.3.	Compare char type value with 'trim'
	21.5.4.	The most useful character specifications are
	21.5.5.	ASCII
	21.5.6.	SUBSTR
	21.5.7.	INSTR
	21.5.8.	Use the SUBSTR and INSTR at the same time.
	21.5.9.	REPLACE
	21.5.10.	TRANSLATE
	21.5.11.	PAD, RPAD, LPAD
	21.5.12.	TRIM
	21.5.13.	Extending your options with regular expressions
	21.5.14.	A Better Routine to Check Social Security Numbers