Because the task parameter mode out

company_id_in
The primary key of the company

status_in
The status of the orders to be included in the sales calculation

shipped_sales := total_sales (company_id, 'S');

all_sales := total_sales (company_id);

OUT Write-only (sort of) The module can assign a value to the parameter, but the parameter’s value cannot be read.

Well, that’s the official version, and a very reasonable definition of an OUT mode parameter. In

PROCEDURE predict_activity

(last_date_in IN DATE,

IN mode

An IN parameter allows you to pass values into the module but will not pass anything out of the module and back to the calling PL/SQL block. In other words, for the purposes of the program, IN parameters function like constants. Just like a constant, the value of a formal IN parameter cannot be changed within the program. You cannot assign values to the IN parameter, or modify its value in any other way, without receiving a compi‐lation error.

DECLARE

happy_title CONSTANT VARCHAR2(30) := 'HAPPY BIRTHDAY';

display_title (happy_title); -- a constant

changing_title := happy_title;