How to get max salary and count from employee table - sql

Question

I have task where I need to filter in such a way that need to print the max(salary * months) and number of times the max(salary * months) occurred.
My data:
employee_id , name , months , salary
12 , Ami , 15 , 1230
14 , Bik , 1 , 678
15 , Tom , 10 , 500
16 , Bob , 12 , 3456
17 , Wil , 1 , 9000
18 , Tim , 14 , 1239
22 , Jil , 15 , 1230
Note: the table as only 4 columns -> employee_id, name, months, salary
I have written a query where I am able to get max(salary * months)
Query #1:
select
max(msal)
from
(select
employee_id,
name,
salary,
months,
(salary * months) as msal
from
employee);
Query #2:
select
e1.employee_id,
e1.months,
e1.salary,
e2.employee_id,
(e2.salary * e2.months) as earnings
from
employee e1
join
employee e2 on e1.employee_id = e2.employee_id;
Query #3:
select
emp,earnings
from
(
select
e1.employee_id as emp,
e1.months,
e1.salary,
e2.employee_id,
(e2.salary * e2.months) as earnings
from
employee e1
join employee e2 on e1.employee_id = e2.employee_id
)
order by
earnings desc;
I calculated on paper these details:
15 * 1230 -> 18450
1 * 678 -> 678
10 * 500 -> 5000
12 * 3456 -> 41472
1 * 9000 -> 9000
14 * 1239 -> 17346
15 * 1230 -> 18450
According my analysis my output should be: 41472 1
41472-> max(salary * months)
1 -> occurred twice

Answer 1

Here's one option:
Sample data:
SQL> with emp (employee_id, name, months, salary) as
2 (select 12, 'ami', 15, 1230 from dual union all
3 select 14, 'bik', 1 , 678 from dual union all
4 select 15, 'tom', 10, 500 from dual union all
5 select 16, 'bob', 12, 3456 from dual union all
6 select 17, 'wil', 1 , 9000 from dual union all
7 select 18, 'tim', 14, 1239 from dual union all
8 select 22, 'jil', 15, 1230 from dual
9 ),
Query begins here: rank values in descending order ...
10 temp as
11 (select salary * months max_value,
12 count(*) cnt,
13 rank() over (order by salary * months desc) rnk
14 from emp
15 group by salary * months
16 )
17 select max_value, cnt
18 from temp
19 where rnk = 1; --> ... and, finally, fetch row(s) that rank as the highest
MAX_VALUE CNT
---------- ----------
41472 1
SQL>
Although you didn't ask for it, but - such an approach is good because you can easily get - for example:
the second highest value simply by modifying the where clause to
where rnk = 2
top 3 values
where rnk <= 3
etc.

Answer 2

You want to look at salary * month results, count their occurence and only show the top figure. So, group by salary * month, count and take the top row:
select salary * month, count(*)
from employee
group by salary * month
order by salary * month desc
fetch first row only;

Answer 3

Finally I was able to write a Query
Incase any efficient way of writing Query. Please provide your solution
Query :
SELECT
msal,
COUNT(*)
FROM
(
SELECT
months * salary AS msal
FROM
employee_salary
WHERE
( months * salary ) IN (
SELECT
MAX(months * salary)
FROM
employee_salary
)
)
GROUP BY
msal;