SELECT a.emp_family_name,SUM((c.sale_price - d.list_price) * c.quantity) as profit FROM employees a,orders b,orderdetails c,items d WHERE a.employeeid = b.employeeid and b.orderid = c.orderid and c.itemid = d.itemid GROUP BY a.emp_family_name HAVING SUM((c.sale_price - d.list_price) * c.quantity) > 0;
FROM employees a,orders b,orderdetails c,items d
WHERE a.employeeid = b.employeeid
and b.orderid = c.orderid
and c.itemid = d.itemid
GROUP BY a.emp_family_name
HAVING SUM((c.sale_price - d.list_price) * c.quantity) > 0;