How can I use SUM function to calculate # of employees in the comp.&deptnt?

Question

I've got two tables: employee & department. I am trying to calculate total employees by department and total employees by the entire company. I know I need to use SUM function, but I only can calculate total employees by department & by company separately. I need to get this output:
DEPT_NAME     DEPT_TOTAL_SALARY         COMPANY_TOTAL_SALARY
RESEARCH                  10875                        29025
SALES                      9400                        29025   
ACCOUNTING                 8750                        29025     
This is my code:
SELECT department_name, SUM(salary) as total_salary
FROM employee, department
WHERE employee.department_id = department.department_id
GROUP BY department_name;
SELECT SUM(salary)
FROM employee;
Can somebody help please?
Thank you in advance.Edited by: user13675672 on Jan 30, 2011 2:29 PM
Edited by: user13675672 on Jan 30, 2011 2:31 PM

Answer 1

Hi, Peter
Peter Gjelstrup wrote:
... There might be a smarter way, with no re-select.You're right, as usual.
SELECT       d.dname
,       SUM (e.sal)               AS dept_tot_sal
,       SUM (SUM (e.sal)) OVER ()     AS comp_tot_sal
FROM       scott.dept     d
JOIN       scott.emp     e  ON     d.deptno     = e.deptno
GROUP BY  d.dname
;Analytic functions are computed after aggregate functions, so an aggregate function can be nested inside an analytic function.
Another way (without a sub-query, at least) would be SELECT DISTINCT, with only analytic functions.
SELECT DISTINCT
       d.dname
,       SUM (e.sal) OVER (PARTITION BY  d.dname)     AS dept_tot_sal
,       SUM (e.sal) OVER ()                    AS comp_tot_sal
FROM       scott.dept     d
JOIN       scott.emp     e  ON     d.deptno     = e.deptno
;