Using special characters in search condition when writing SQL queries

1- SELECT name FROM emp
 WHERE id LIKE '%/_%' ESCAPE '/';

2-  When using SQL*Plus, the DEFINE setting can be changed to allow &'s (ampersands) to be used in text:

 SET DEFINE ~
 SELECT 'Laurel & Hardy' FROM dual;

3-

  SET ESCAPE '\'
  SELECT '\&abc' FROM dual;
 
4-
  SET SCAN OFF
  SELECT '&ABC' x FROM dual;