Adding a cursor in with a PL/SQL statement?

Question

I have two tables department and employee and this PL/SQL statement that displays company average salary.

DECLARE
  v_cavg NUMBER;
BEGIN
  SELECT avg(salary) into v_cavg FROM employee;
  DBMS_Output.Put_Line('Company Average Salary: ' ||    RTRIM(TO_CHAR(v_cavg,'$999G999G999D99')));
  DBMS_Output.Put_Line('----------------------------------------');
END;

What I am trying to do now is implement a cursor and join together the employee and department tables to get all department names that have a department average salary less than that of the company average salary. I am brand new to cursors and I know I have to have an if statement somewhere along these lines

if v_davg < v_cavg THEN
     DBMS_OUTPUT_.PUT_LINE ('Department Name: ' || RPAD(v_dname);
     DBMS_Output.Put_Line('Department Average Salary: ' ||    RTRIM(TO_CHAR(v_davg,'$999G999G999D99')));
  DBMS_Output.Put_Line('----------------------------------------');
else
     DBMS_Output.Put_Line(' '); /// Nothing here.
 END IF;
END;

I am just not sure how to add in a cursor any help would be great!

Answer 1

You actually don't need a cursor, or an IF statement:

SELECT d.name, avg(e.salary)
FROM department d, employee e
GROUP BY d.name
HAVING avg(e.salary) > v_cavg;

If the formatting of the output is important, you could use a cursor to loop through these results like so:

DECLARE

  CURSOR c IS
  SELECT...(as above);

BEGIN

  FOR r IN c LOOP
    dbms_output.put_line('Department Name: '||r.name);
    -- Etc, etc.
  END LOOP;

END;

Answer 2

A simple statement would help.

10:17:37 HR@sandbox> ed
Wrote file S:\tools\buffer.sql

  1  select d.department_name
  2    from departments d
  3         ,employees e
  4   where d.department_id = e.department_id
  5   group by d.department_name
  6*  having avg(salary) < (select avg(salary) from employees)
10:18:23 HR@sandbox> /

DEPARTMENT_NAME
------------------------------
Administration
Purchasing
IT
Shipping

Elapsed: 00:00:00.09

You can also wrap it in a cursor like this:

10:18:23 HR@sandbox> ed
Wrote file S:\tools\buffer.sql

  1  begin
  2    for i in (
  3      select d.department_name
  4        from departments d
  5             ,employees e
  6       where d.department_id = e.department_id
  7       group by d.department_name
  8       having avg(salary) < (select avg(salary) from employees)
  9     ) loop
 10       dbms_output.put_line(i.department_name);
 11     end loop;
 12* end;
10:20:29  13  /
Administration
Purchasing
IT
Shipping

PL/SQL procedure successfully completed.

Elapsed: 00:00:00.07

Notice the IT department traditionally being one of those with the lowest salary.