This document provides instructions for creating a query in MS Access to calculate the cost of hiring a costume. It explains that the query will multiply the number of days rented from the Costume table by the day rate stored in the CostumeHireGroup table. It instructs the user to add the necessary fields from both tables to the design view of an existing date query, then add the calculation expression [Days rented] * [Day rate] to a new column where Access will provide a name. Finally, the user can edit the column heading to make it more meaningful.

1. MS Access How To:
Calculate Queries
Unit 18 Database Design
Extended Diploma in ICT

2. Purpose
• You may need to calculate a result from the
contents of fields
• This is done by building the expression in the
field row of a column
• In this example we will create a query to
calculate the cost of hiring a costume
• This will build on the date query (see How To:
Date Queries)

3. Data source
• The rental rate is in the CostumeHireGroup
table
• We need the Costume table as well to show
the relationships
• Add these tables to the design view of the
date query

4. Add the fields
• Add the CostumeType and DayRate fields to
the query

5. Adding the calculation
• Add the following to the field row in a column
• [Days rented] * [Day rate]
• Access will add an expression name

6. Changing the heading
• You can edit the heading to make it more
meaningful

7. Changing the heading
• You can edit the heading to make it more
meaningful