Question on cursors

Question

Hello,
I want to retrieve all names and salaries from an employee table based on the number of records shown of what the user inputs and retrieve all names of the salaries that is included in the top n if it matches other employee salaries. For example in the accept command, if a user entered 5 it should show 5 records plus the names of people who have the same record.
Another example in the table there are 3 records:
Sue 2000
Blake 2000
Mary 1000
I enter 2 in the accept command, it should bring back all three records because one of the salaries of the employee matches another employee.
I think the problem I'm having is I do not know what to initialize salary to.
Here's what I got:
ACCEPT p_number PROMPT 'Please enter the number of top money makers: '
DECLARE
v_number NUMBER(4) := &p_number;
v_sal emp.sal%TYPE;
v_count NUMBER;
CURSOR sal_cursor IS
SELECT ename, sal from emp
where sal = v_sal; --I think this is the problem.  What do I initialize v_sal to?
sal_rec sal_cursor%ROWTYPE;
BEGIN
OPEN sal_cursor;
DBMS_OUTPUT.PUT_LINE('Name' || chr(9) || 'Salary');
v_count := 0;
LOOP
FETCH sal_cursor INTO sal_rec;
v_count + 1;
EXIT WHEN v_count > v_number OR
sal_cursor%NOTFOUND;
DBMS_OUTPUT.PUT_LINE(sal_rec.ename || chr(9) || chr(9) || chr(9) || sal_rec.sal);
END LOOP;
CLOSE sal_cursor;
INSERT INTO top_dogs values (sal_rec.ename, sal_rec.sal);
END;
Any help would be greatly appreciated.

Answer 1

I think you are probably looking for DENSE_RANK, or possibly RANK, depending on how you feel about ties.
SQL> WITH emp AS (SELECT 'Sue' emp_name, 2000 sal FROM dual UNION ALL
  2               SELECT 'Blake', 2000 FROM dual UNION ALL
  3               SELECT 'Mary', 1000 FROM dual UNION ALL
  4               SELECT 'Steve', 900 FROM dual)
  5  SELECT emp_name, sal, rnk, drnk
  6  FROM (SELECT emp_name, sal,
  7               RANK() OVER (ORDER BY sal DESC) rnk,
  8               DENSE_RANK() OVER (ORDER BY sal DESC) drnk
  9        FROM emp)
EMP_N        SAL        RNK       DRNK
Sue         2000          1          1
Blake       2000          1          1
Mary        1000          3          2
Steve        900          4          3Note that you can do this without PL/SQL something like:
SQL> !cat t.sql
ACCEPT p_number PROMPT 'Please enter the number of top money makers: '
WITH emp AS (SELECT 'Sue' emp_name, 2000 sal FROM dual UNION ALL
             SELECT 'Blake', 2000 FROM dual UNION ALL
             SELECT 'Mary', 1000 FROM dual UNION ALL
             SELECT 'Steve', 900 FROM dual)
SELECT emp_name, sal, rnk, drnk
FROM (SELECT emp_name, sal,
             RANK() OVER (ORDER BY sal DESC) rnk,
             DENSE_RANK() OVER (ORDER BY sal DESC) drnk
      FROM emp)
WHERE drnk <= &p_number;
SQL> @t
Please enter the number of top money makers: 2
old  10: WHERE drnk <= &p_number
new  10: WHERE drnk <= 2
EMP_N        SAL        RNK       DRNK
Sue         2000          1          1
Blake       2000          1          1
Mary        1000          3          2John