Double Cursors

1)double cursors
DECLARE
  CURSOR cursor_dept IS
    SELECT DISTINCT department_id, department_name
    FROM departments
    WHERE department_id < 100;
  CURSOR cursor_emp( dept_id NUMBER ) IS
    SELECT last_name, job_id, hire_date, salary
    FROM employees
    WHERE employee_id < 120
      AND department_id = dept_id;
  cur_r_dept  cursor_dept%ROWTYPE;
  cur_r_emp    cursor_emp%ROWTYPE;
BEGIN
--first cursor begin
  OPEN cursor_dept;
    LOOP     --<<outer loop begin>>
      FETCH cursor_dept INTO cur_r_dept;
      EXIT WHEN cursor_dept%NOTFOUND
             OR cursor_dept%NOTFOUND is null;
--second cursor begin 
        IF cursor_emp%ISOPEN THEN CLOSE cursor_emp; END IF;
        OPEN cursor_emp( cur_r_dept.department_id );
          LOOP       --<<inner loop begin>>
            FETCH cursor_emp INTO cur_r_emp;
            EXIT WHEN cursor_emp%NOTFOUND
                   OR cursor_emp%NOTFOUND is null;       
            DBMS_OUTPUT.put_line(cur_r_emp.last_name ||' '
            ||cur_r_emp.job_id || ' '
            ||cur_r_emp.hire_date || ' '
            ||cur_r_emp.salary );
          END LOOP;  --<<inner loop end>>
        IF cursor_emp%ISOPEN THEN CLOSE cursor_emp; END IF;
    END LOOP; --<<outer loop end>>
  IF cursor_emp%ISOPEN THEN CLOSE cursor_emp; END IF;
  CLOSE cursor_dept;
END;
/


2)double cursors, change record
DECLARE
  CURSOR dept_cursor IS
    SELECT department_id, department_name
    FROM departments
    WHERE department_id < 100 ORDER BY department_id;
  CURSOR emp_cursor( v_deptno NUMBER) IS
    SELECT last_name, job_id, hire_date, salary
    FROM employees
    WHERE department_id = v_deptno
      AND employee_id < 120;
  v_current_deptno  departments.department_id%TYPE;
  v_current_dname   departments.department_name%TYPE;
  v_ename           employees.last_name%TYPE;
  v_job             employees.job_id%TYPE;
  v_hiredate        employees.hire_date%TYPE;
  v_sal             employees.salary%TYPE;
BEGIN
--First cursor begin
  OPEN dept_cursor;
    LOOP
      FETCH dept_cursor INTO v_current_deptno, v_current_dname;
      EXIT WHEN dept_cursor%NOTFOUND;
      DBMS_OUTPUT.put_line('Department Number: ' || v_current_deptno
      || ' Department Name: ' || v_current_dname);
      DBMS_OUTPUT.put_line(chr(13));
--Second cursor begin
        IF emp_cursor%ISOPEN THEN CLOSE emp_cursor; END IF;
        OPEN emp_cursor( v_current_deptno);
          LOOP
            FETCH emp_cursor INTO v_ename,v_job,v_hiredate,v_sal;
            EXIT WHEN emp_cursor%NOTFOUND;
            DBMS_OUTPUT.put_line(v_ename ||', '
            ||v_job||', '
            ||v_hiredate ||', '
            ||v_sal );
          END LOOP;
        IF emp_cursor%ISOPEN THEN CLOSE emp_cursor; END IF;
      DBMS_OUTPUT.put_line(chr(13));
    END LOOP;
  IF emp_cursor%ISOPEN THEN CLOSE emp_cursor; END IF;
  CLOSE dept_cursor;
END;
/