Packages have objects (they own them as tables own their columns).
Objects can be (not limited to):
- packages
- functions
- variables
Think of a package in pl/sql as a logical grouping. For example, if there's a students package, it may have::
- a package variable that reflects if the study term is open or not
- procedures that process time table allocations ( does not need to return any value and runs after work hours in batch mode)
- functions that return statistics of students. For example, counts of local, interstate and overseas students in a given semester
Example:
CREATE OR REPLACE PACKAGE BODY students_pkg
IS
term_active ....
PROCEDURE allocate_timetables
.....
FUNCTION get_local_students_count
....
RETURN count NUMBER;
....
FUNCTION get_overseas_students_count
....
RETURN count NUMBER;
....
FUNCTION get_interstate_students_count
....
RETURN count NUMBER;
....
BEGIN
-- initialisation codes live here
-- assign default values to objects here
-- execute whatever logic/code here
END students-pkg;
Outside the package, we use it...
DECLARE
...
BEGIN
IF students_pkg.terms THEN
DBMS_OUTPUT.PUT_LINE( "Number of local students in this term is " || students_pkg.get_local_students_count );
END IF;
EXCEPTION
...
END;
