I want to view the top 300 items ordered by total net price, how do I do this please?

Using SSMS 2014

If I remove group by I get error: Column 'orderitems.orderid' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.

Please see workings below:

```
select top 300

orderitems.orderid, orders.traderid, orders.orderdate, 
SUM(orderitems.nettprice) AS nettprice

from orderitems

INNER JOIN orders ON orders.tradertype = 'S' AND orders.id = 
orderitems.orderid 

where orderitems.ordertype = 'PO'

group by orderitems.orderid, orders.traderid, orders.orderdate, 
orderitems.nettprice

order by orderitems.nettprice  DESC

```