How to get difference the min of two columns having different conditions ?

Question

Hello,
I am trying to write a query which staisfies the following condittion. I have a table emp which has the following colums empno,ename,deptcode,empstat_code,salary.
The salary of employees depends on the empstat_code.
For a given deptcode, I have to compare the mimimum of salaries for empstat_code 'A' with the minimum of salaries for empstat_code 'B' and then a get a difference between the two.
How can I do this, please advise.
Thanks
fm

Answer 1

Something like this perhaps.
create table my_emp as
select
from scott.emp
alter table my_emp add emp_stat varchar2(1);
update my_emp set emp_stat= case when mod(rownum, 2) = 0 then 'A' else 'B' end;
select * from my_emp;
TUBBY_TUBBZ?select
  2        min(decode(emp_stat, 'A', sal)) as min_A_sal
  3     ,  min(decode(emp_stat, 'B', sal)) as min_B_sal
  4     ,  deptno
  5  from
  6     my_emp
  7  group by
  8     deptno;
         MIN_A_SAL          MIN_B_SAL             DEPTNO
               950               1250                 30
              2975                800                 20
              1300               2450                 10
3 rows selected.
Elapsed: 00:00:00.71Keeping in mind that MIN will return NULL if there are no values for a given emp_stat and deptno combination. So you would have to account for that however your business rules tell you to account for it (likely using NVL to 0)