PL/SQL SET Serveroutput ON

Whenever you start Oracle SQL (PL/SQL) at that time you must have to write the "SET Serveroutput ON" command.
PL/SQL program execution into Oracle engine so we always required to get serveroutput result and display into the screen otherwise result can't be display.

Set PL/SQL serveroutput Result ON

SQL> set serveroutput on 

Set serveroutput on Example

In this example showing you how to turn on serveroutput result, Here first line turn on serveroutput. After define variables and constants to print defined variable value using dbms_output.put_line command.
Example Code :

SQL> set serveroutput on
SQL> DECLARE
 eno number(5) NOT NULL := 2
 ename varchar2(15) := 'Branson Devs';
 edept CONSTANT varchar2(15) := 'Web Developer';
BEGIN
 dbms_output.put_line('Declared Value:');
 dbms_output.put_line(' Employee Number: ' || eno || ' Employee Name: ' || ename);
 dbms_output.put_line('Constant Declared:');
 dbms_output.put_line(' Employee Department: ' || edept);
END;
/

Result display only if you execute "set serveroutput on" command.
Example Result :

Declared Value:
Employee number: 2 Employee Name: Branson Devs
Constant Declared:
Employee Department: Web Developer