ORACLE PL/SQL ... if dbms_output.put_line('Hello World'); does not work...

If  dbms_output.put_line('Hello World'); in your PL/SQL script does not work, you probably forgot to activate the output in your SQLPLUS.exe or SQL Developer!


To activate the output, enter the following command:


set serveroutput on


Now you can execute your function/procedure:



begin
dbms_output.put_line('Hello World');
end;
/

Execute a script with sqlplus

To execute a sql-script with sqlplus just insert your this command:

(replace  : username, password, connection_string, /path/to/script)

echo exit | sqlplus username/password@connection_string@/path/to/script

Source:

http://serverfault.com/