How To Use “IN” Parameter Properly?
• A formal IN parameter acts like constant. It can not be assigned with new values. • An actual IN parameter can take a value or a variable. • An actual IN parameter is passed by reference to the specified value or the value of the specified variable. • An actual IN parameter will not receive any value from the formal parameter.Here is good example of a procedure with an IN parameter: SQL> CREATE OR REPLACE PROCEDURE WELCOME AS 2 SITE CHAR(80) := ‘FYICenter.com’; 3 PROCEDURE WELCOME_PRINT(S IN CHAR) AS 4 BEGIN 5 DBMS_OUTPUT.PUT_LINE(’Welcome to ‘ || S); 6 – S := ‘Google.com’; — Not allowed 7 END; 8 BEGIN 9 WELCOME_PRINT(’MySpace.com’); 10 WELCOME_PRINT(SITE); 11 END; 12 / SQL> EXECUTE WELCOME; Welcome to MySpace.com Welcome to FYICenter.com How To Use “OUT” Parameter Properly? Here are the rules about OUT parameters: • A formal OUT parameter acts like an un-initialized variable. It must be assigned with new values before the end of the procedure or function. • An actual OUT parameter m
