Access IIf function

[Tricia1123]

I have a query that has StartDate, EndDate and RentalRate Fields. I need to calculated a field named Total Due that multiplies the value of the RentalRate field by the number of days for the trip. The hint I was given "Subtract the StartDate field value from the EndDate field value and add 1". I tried a number of expressions but nothing is working right.

[NeoPa]

Try :

SELECT ..., ([EndDate]+1-[StartDate])*[RentalRate) AS [Total Due]
FROM ...