You can use GROUP BY additionally with GROUPING SETS.

If you've been useing GROUP BY for a number of columns, now imagine those columns as sets, and everything is the same. When you use sets to make the groupation you have to add the GROUPING SETS as reserved words.

For example, the following select using GROUPING SETS

SELECT Region, Department, avg(sal) AverageSalary

from tblEmployee

Group BY

GROUPING SETS

(

(Region, Department)

/*

(Region),

(Department) ,

()

*/

)

is equal to the following with only GROUP BY

SELECT Region, Department, avg(sal) AverageSalary

from tblEmployee

Group BY

Region, Department

Regards,

IgorMi