Hello every one i just was told about this site today and i could use some help. I have read the rules and i understand what i am doing code wise well we just started Pl sql last week before that i had only done basic sql. but now i am stuck on calling the function i made :/ i feel silly. It is a fairly straight forward function and i am sure it is correct as my sql teacher said 'it looks good at a glance' but she did not show me how to call the functions and i really want to see if it working.
I know how to call basic sql and functions and pl sql with dbms.out but i draw a blank here, i remember her saying use 1 instead of employee_no in the select and its just two lines to call it please please can some one show me how to call what i made. I attached the ERD below too.
(a) to calculate and return the total number of different task-types a given employee has worked on.
SHOW ERRORS
CREATE OR REPLACE FUNCTION task_types(eno employee.employee_no%TYPE)
RETURN NUMBER IS
task_var task.task_type_no%TYPE;
BEGIN
SELECT COUNT(DISTINCT t.task_type_no)
INTO task_var
FROM employee e, task t, assignment a
WHERE e.employee_no = a.employee_no
AND a.task_id = t.task_id
AND e.employee_no = eno;
RETURN task_var;
END;
Entity-relational diagram:

Thank you :)