Omnidex SQL: SELECT GROUP_BY Clause

  GROUP BY group_by_columns
      [ HAVING [ left_operand operator subquery ]
               [ left_operand IN (subquery) ] ]

Column Names From the Select List

select customer_no, sum(amount) from orders group by customer_no

select city, state, count(distinct company) from customers group by city, state

Column Names Not in the Select List

select status, sum(amount) from orders group by customer_no, status

select count(company) from customers group by state

Having

select customer_no, sum(amount) from orders 
   group by customer_no having customer_no = 1001;

select customer_no, sum(amount) from orders 
   group by customer_no having status != 'shipped';

select status, sum(amount) from orders group by status having customer_no 
   in (select customer_no from customers where company='systems');