Chapter 9 - Using Queries to Select Data

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In Chapter 2, "Overview of Basic Access Features," you learned that queries are used to sort, filter, add, delete, and modify data in Microsoft Access databases. In this chapter, you’ll learn how to use queries to request data for forms, reports, and controls when an object relies on specific data rather than on all the data in the underlying table. There are several query types, as follows:

• Select queries. These queries retrieve data that meets specific conditions, group records for viewing summary data, and display calculations performed on data fields.
• Action queries. These queries modify existing data in some way. You can use action queries to delete, update, and append data or to create a new table.
• Parameter queries. These queries prompt you for criteria before running the actual query.
• Crosstab queries. These queries summarize data and then group the summarized values into categories.
• SQL queries. These queries, which include union, pass-through, and data-definition queries, require specific SQL commands that you must compose in SQL view. (Design view is not available for SQL queries.)

This chapter on selecting data will examine the simpler aspects of working with the select query, which you’ll rely on to perform the following tasks:

• Retrieve, sort, and group data
• Limit results
• Evaluate expressions

This chapter also includes discussions of joins and crosstab queries.