Getting a PL/SQL Cursor for loop to work with input variable? - sql

Question

I have to produce PL/SQL block that takes the input in of an integer where n (1 ≤ n ≤ 100) and display the most popular names for male and female. If the number entered is out of that range display an invalid input. I have created a table called popular names that has 100 of the most popular names for male and female. I am struggling with my FOR loop and getting it to work with the user input. My code is below:
ACCEPT p_1 prompt 'please enter an integer between 1 and 100'
DECLARE
CURSOR name_cur IS
SELECT rank, male_given_name, female_given_name
FROM popular_names
ORDER BY rank;
v_nrank popular_names.rank%TYPE := &p_1;
v_nmale popular_names.male_given_name%TYPE;
v_nfemale popular_names.female_given_name%TYPE;
BEGIN
OPEN name_cur;
FETCH name_cur INTO v_nrank, v_nmale, v_nfemale;
IF name_cur%FOUND THEN
DBMS_OUTPUT.PUT_LINE('Rank Male Given Name Female Given Name');
DBMS_OUTPUT.PUT_LINE('----------------------------------------------');
FOR i IN 1..v_nrank LOOP
DBMS_OUTPUT.PUT_LINE((RPAD(v_nrank, 18) || ' ' ||
(RPAD(v_nmale, 18) || ' ' || v_nfemale)));
FETCH name_cur INTO v_nrank, v_nmale, v_nfemale;
EXIT WHEN name_cur%NOTFOUND;
END LOOP;
ELSE
DBMS_OUTPUT.PUT_LINE('Invalid number!');
END IF;
CLOSE name_cur;
END;

Answer 1

No need for cursor. Or use similar query in your cursor. You can use Rownum pseudocolumn in place of Row_Number() function:
SELECT * FROM
(
SELECT deptno
, empno
, ename
, Row_Number() OVER (ORDER BY empno) AS row_seq -- can order/partition by any field
-- , Rownum AS row_seq
FROM scott.emp
)
WHERE row_seq BETWEEN 1 AND 10 -- any integer as in your example --
/
DECLARE
CURSOR e_cur
IS
SELECT * FROM
(
SELECT deptno
, empno
, ename
, Row_Number() OVER (ORDER BY empno) AS row_seq --'AS' is for clarity-not required
--, Rownum AS row_seq
FROM scott.emp
)
WHERE row_seq BETWEEN 1 AND 10 -- any integer, can use variable like &num --
ORDER BY row_seq;
v_deptno scott.dept.deptno%TYPE;
v_emp_no scott.emp.empno%TYPE;
v_name scott.emp.ename%TYPE;
v_rank NUMBER;
BEGIN
OPEN e_cur;
LOOP
FETCH e_cur INTO v_deptno, v_emp_no, v_name, v_rank;
EXIT WHEN e_cur%NOTFOUND;
dbms_output.put_line(v_rank||chr(9)||v_deptno||chr(9)||v_emp_no||chr(9)||v_name);
END LOOP;
CLOSE e_cur;
END;
/