Microsoft Access Tutorial B - Cengage Learning

You already know how to do certain things for this query. The revised heading for theaverage rate will be Average Rate (Average Rate: Wage Rate, in the Field cell). You want theAverage of that field. Grouping would be by the Salaried field (with Criteria: =No, for hourlyworkers).The most difficult part of this query is to construct the expression for the calculated field.Conceptually, it is as follows:Increased Rate: 1.1*[The current average, however that is denoted]The question is how to represent [The current average]. You cannot use Wage Rate forthis, because that heading denotes the wages before they are averaged. Surprisingly, it turnsout that you can use the new heading (Average Rate) to denote the averaged amount. Thus:Increased Rate: 1.1*[Average Rate]Counterintuitively, you can treat “Average Rate” as if it were an actual field name. Note,however, that if you use a calculated field, such as Average Rate, in another calculated field,as shown in Figure B-30, you must show that original calculated field in the query output, orthe query will ask you to “enter parameter value,” which is incorrect. Use the set-up shown inFigure B-30.Tutorial BFigure B-30Using a calculated field in another calculated fieldHowever, if you ran the query now shown in Figure B-30, you’d get some sort of errormessage. You do not want Group By in the calculated field’s Total cell. There is not a statisticaloperator that applies to the calculated field. You must change the Group By operator toExpression. You may have to scroll to get to Expression in the list. Figure B-31 shows howyour screen should look.Microsoft Access Tutorial 27