Try

SELECT t1.sono, t1.tcode, t1.tdate ;
	FROM mytable t1 ;
	WHERE t1.tdate = (SELECT MAX(tdate) FROM mytable t2 ;
					WHERE t1.sosno = t2.sono AND t1.tcode = t2.tcode)

>I have a table with sales order number (sono), Transaction Code (tcode) and transaction date (tdate) fields.
>There are multiple records for one Sales Order.
>I want to write a query that returns one record with the sono, tcode and tdate for the latest date for that sales order and I have a complete blank