Use the Least functions : LEAST « Miscellaneous Functions « Oracle PL/SQL Tutorial

1. Oracle PL/SQL Tutorial
2. Miscellaneous Functions
3. LEAST

SQL>
SQL>
SQL> SET SERVEROUTPUT ON
SQL> DECLARE
  2     v_char VARCHAR2(10);
  3     v_number NUMBER(10);
  4  BEGIN
  5
  6     v_char := LEAST('A', 'B', 'C');
  7     v_number := LEAST(1,2,3);
  8
  9     DBMS_OUTPUT.PUT_LINE('Least Character: '||v_char);
 10     DBMS_OUTPUT.PUT_LINE('Least Number: '||v_number);
 11
 12
 13  END;
 14  /
Least Character: A
Least Number: 1

PL/SQL procedure successfully completed.