Summarizing Query Results

When you create aggregate queries, certain logical principles apply. For example, you cannot display the contents of individual rows in a summary query. The Query and View Designer helps you comply with these principles in the way the Diagram Pane and Criteria Pane behave.

By understanding the principles of aggregate queries and the Query and View Designer's behavior, you can create logically correct aggregate queries. The overriding principle is that aggregate queries can result only in summary information. Thus, most of the principles that follow describe the ways that you can reference individual data columns within an aggregate query.

In This Section

• Working with Columns in Aggregate Queries
  Describes concepts about grouping and summarizing columns with the GROUP BY, WHERE, and HAVING clauses.

• How to: Count Rows in a Table
  Provides steps for counting the number of rows in a table or the number of rows in a table that meet a set of criteria.

• How to: Summarize or Aggregate Values for All Rows in a Table
  Provides steps for summarizing all rows rather than for a set of grouped rows.

• How to: Summarize or Aggregate Values Using Custom Expressions
  Provides steps for using expressions to summarize or aggregate rather than using the predefined clauses.

Reference

• Reference (Visual Database Tools)
  Provides links to general reference topics covering queries, operators, search conditions, specific DBMS requirements, user interface reference topics, and error message topics.

Related Sections

• Designing Queries and Views
  Provides links to topics covering how to use the Query and View Designer.