Help needed with analytical function

Question

I want to get the employee details of the highest and 2nd highest salaried employee in a particular department. But also the department should have more than 1 employee.
I tried the query and it gave me proper results. But I'm wondering if there is some other alternative than using the subquery.
Here is the table and the result query :
with t as
select 1 emp_id,3 mgr_id,'Rajesh' emp_name,3999 salary,677 bonus,'HR' dpt_nme from dual union
select 2 ,3 ,'Gangz',4500,800,'Finance' from dual  union
select 3 ,4 ,'Sid',8000,12000,'IT' from dual  union
select 4 ,null,'Ram',5000,677,'HR' from dual  union
select 5 ,4,'Shyam',6000,677,'IT' from dual union
select 6 ,4 ,'Ravi',9000,12000,'IT' from dual  
select * from
(select emp_id, mgr_id, emp_name, dpt_nme, salary, row_number() over (partition by dpt_nme order by salary desc) rn from t where dpt_nme in
(select dpt_nme from t group by dpt_nme having count(*) > 1)) where rn < 3

Answer 1

Hi,
You need a sub-query, but you don't need more than that.
Here's one way to eliminate the extra sub-query:
WITH     got_analytics     AS
     SELECT  emp_id,     mgr_id,     emp_name, dpt_nme, salary
     ,     ROW_NUMBER () OVER ( PARTITION BY  dpt_nme
                               ORDER BY          salary     DESC
                       )         AS rn
     ,     COUNT (*)     OVER ( PARTITION BY  dpt_nme
                                   )         AS dpt_cnt
     FROM     t
SELECT  emp_id,     mgr_id,     emp_name, dpt_nme, salary
,     rn
FROM     got_analytics
WHERE     rn     < 3
AND     dpt_cnt     > 1
;Analytic functions are computed after the WHERE clause is applied. Since we need to use the results of the analytic ROW_NUMBER function in a WHERE clause, that means we'll have to compute ROW_NUMBER in a sub-query, and use the results in the WHERE clause of the main query. We can call the analytic COUNT function in the same sub-query, and use its results in the same WHERE clause of the main query.
What results would you want if there's a tie for the 2nd highest salary in some department? For example, if you add this row to your sample data:
select 7 ,3 ,'Sunil',8000,12000,'IT' from dual  union? You may want to use RANK instead of ROW_NUMBER.