SQL-92 provided a case expression that would seem to offer a way out. Put both quarters' data into the query, and then sort out the two quarters in the select list. The first CASE expression tests each record in the candidate answer set. If the Time. Quarter is 4Q95, then Sales.
Quarter is something else, zero is added.
The same logic applies to the second case statement, except that the time period is 4Q94. This logic allows the two Sales. Dollar columns to be computed. Unfortunately, several things are wrong with this scenario. First, I don't know of a query tool that supports building this kind of logic.