PL/SQL CONSTANT

상수선어에 일반적인 구문
constant_name CONSTANT datatype := VALUE; 
 
For example, to declare salary_increase, you can write code as follows: 
 
DECLARE 
salary_increase CONSTANT number (3) := 10; 
 
 
You must assign a value to a constant at the time you declare it. If you do not assign a value to a constant while declaring it and try to assign a value in the execution section, you will get a error. If you execute the below Pl/SQL block you will get error. 
 
DECLARE 
 salary_increase CONSTANT number(3); 
BEGIN 
 salary_increase := 100; 
 dbms_output.put_line (salary_increase); 
END;