About this Article:
The Pareto rule says that 80 percent of your benefits (and problems) come from 20 percent of your population. As a result, you often want to look at only a small part of your data -- the part that matters. The Top query, a powerful, yet little known feature of Access' version of SQL lets you limit the results of a query to a certain number (or percentage) of records. One of the reasons the query isn't used more is because the name top is deceiving: Many developers assume a Top Query returns only the largest values. However, this isn't the case. You can choose, for instance, to retrieve the largest values or, just as easily, retrieve the smallest values. As you'll learn, you can even choose random records.
Roger Carlson graduated from Western Michigan University with a BS in Computer Science and taught database design and implementation at Muskegon Community College for 12 years. His Web site has been visited by over quarter of a million visitors from 170 countries and from which an estimated three million samples have been downloaded. In January of 2006, he was awarded the Microsoft Access MVP (Most Valuable Professional) award. Roger works at Spectrum Health, the largest hospital system in out-state Michigan, as a Senior Clinical Decision Support Analyst in the Quality Improvement Department. www.rogersaccesslibrary.com