Sales by Months and Years
1. Sales by Month
select c.company, extract(month from saledate) field, sum(itemstotal) "VALUE"
from customer c join orders o on o.custno=c.custno
group by 1,2
order by 1
2. Sales by Year
select c.company, extract(year from saledate) field, sum(itemstotal) "VALUE"
from customer c join orders o on o.custno=c.custno
group by 1,2
order by 1