Need a procedure with in, out, in out parameters - small example.

Question

Hi Masters,
Need a small example with 3 parameters in a procedure. How to know call by value and call by reference with out and inout parameters.
create or replace procedure sample(x in number, y out number, z in out number) is
begin
     pass the x value into y and z as well. and display the 3 values.   Code requried..
end;
Thanks a lot in adv.
AR

Answer 1

Hi,
874273 wrote:
Hi Masters,
Need a small example with 3 parameters in a procedure. How to know call by value and call by reference with out and inout parameters.
create or replace procedure sample(x in number, y out number, z in out number) is
begin
     pass the x value into y and z as well. and display the 3 values.   Code requried..
end;
Thanks a lot in adv.
AR
I'm not sure I understand the question.
In PL/SQL, the way to pass the value of x to another variable v is:
v := x;
Here, v can be an OUT argument or an IN OUT argument.  (It can be any kind of variable except an IN argument or a CONSTANT.)
PL/SQL doesn't really have any way to display values.  For debugging, people often use dbms_output, like this:
dbms_output.put_line (y || ' = y inside sample procedure');
Many front end tools (such as SQL*Plus) can display the text after PL/SQL finishes.
By default, all arguments in PL/SQL are passed by value.  To call by reference, use the NOCOPY hint, as shown below:
SET SERVEROUTPUT ON;
CREATE OR REPLACE PROCEDURE sample ( x  IN              NUMBER
                                   , y  OUT             NUMBER
                                   , z  IN OUT  NOCOPY  NUMBER
IS
BEGIN
     y := x;
     z := x;
     dbms_output.put_line (y || ' = y inside sample procedure');
     dbms_output.put_line (z || ' = z');
END sample;
SHOW ERRORS