MS Access for the Business Environment: Access Query Techniques: Using the TOP Keyword

About the Series …

This article continues the series, MS Access for the
Business Environment
. The primary focus of this series is an
examination of business uses for the MS Access relational database management
system. The series is designed to provide guidance in the practical application
of data and database concepts to meet specific needs in the business world. The
majority of the procedures I demonstrate in this article and going forward will
be undertaken with MS Access 2003, although most of the concepts that we
explore in the series will apply to earlier versions of MS Access, as well.

For more information on the series, as well as the hardware
/ software requirements to prepare for the tutorials we will undertake, please
see Tutorial 1: Create
a Calculated Field with the Expression Builder
.

Introduction to this
Tutorial

In our
last lesson, Access
Query Techniques: Subqueries, Part I
, we
introduced subqueries within the context of MS Access, and practiced their
creation and use in rendering a result dataset to meet illustrative business
needs. As a part of our exploration of subqueries, we examined the syntax
surrounding the use of a straightforward sample subquery; we then began an
illustrative, hands-on example of the use of a subquery in a multi-step
practice exercise. After evolving an initial query, we created a second query,
within which we nested the first, to demonstrate the operation of a subquery in
our practice exercise. Finally, we briefly discussed various aspects of the
results datasets that we obtained in each step of the practice examples.

Before moving to our next
article, Access Query Techniques: Subqueries,
Part II
, we will
first consider a keyword whose use we will see again in the second half of our
exploration of subqueries, as well as elsewhere. We will overview the TOP
keyword, and get a feel for its operation in an undistracted scenario, before
proceeding into the creation of a subquery that leverages the keyword to
illustrate more sophistication in the use of subqueries than we saw in Part
I
.

The objective of this lesson is
to introduce the TOP keyword as it is used in Microsoft Jet SQL, and to
explore ways we can use it to meet illustrative business needs. To accomplish
this, we will follow our approach in previous lessons, and perform the
following activities surrounding our examination of the TOP keyword:

  • an examination of the syntax surrounding the use of TOP;

  • an illustrative, hands-on example of the use of TOP in a practice
    exercise;

  • a similar example where we use the optional PERCENT
    keyword, in conjunction with TOP, to return a percentage, versus a
    number, of rows in an illustrative dataset;

  • a brief discussion of the results datasets that we obtain in each
    of the practice examples.

We will use the Northwind sample database that
installs with MS Access for purposes of this lesson, in an attempt to make our
discussion useful to virtually anyone who has access to the application.

William Pearson
William Pearson
Bill has been working with computers since before becoming a "big eight" CPA, after which he carried his growing information systems knowledge into management accounting, internal auditing, and various capacities of controllership. Bill entered the world of databases and financial systems when he became a consultant for CODA-Financials, a U.K. - based software company that hired only CPA's as application consultants to implement and maintain its integrated financial database - one of the most conceptually powerful, even in his current assessment, to have emerged. At CODA Bill deployed financial databases and business intelligence systems for many global clients. Working with SQL Server, Oracle, Sybase and Informix, and focusing on MSSQL Server, Bill created Island Technologies Inc. in 1997, and has developed a large and diverse customer base over the years since. Bill's background as a CPA, Internal Auditor and Management Accountant enable him to provide value to clients as a liaison between Accounting / Finance and Information Services. Moreover, as a Certified Information Technology Professional (CITP) - a Certified Public Accountant recognized for his or her unique ability to provide business insight by leveraging knowledge of information relationships and supporting technologies - Bill offers his clients the CPA's perspective and ability to understand the complicated business implications and risks associated with technology. From this perspective, he helps them to effectively manage information while ensuring the data's reliability, security, accessibility and relevance. Bill has implemented enterprise business intelligence systems over the years for many Fortune 500 companies, focusing his practice (since the advent of MSSQL Server 2000) upon the integrated Microsoft business intelligence solution. He leverages his years of experience with other enterprise OLAP and reporting applications (Cognos, Business Objects, Crystal, and others) in regular conversions of these once-dominant applications to the Microsoft BI stack. Bill believes it is easier to teach technical skills to people with non-technical training than vice-versa, and he constantly seeks ways to graft new technology into the Accounting and Finance arenas. Bill was awarded Microsoft SQL Server MVP in 2009. Hobbies include advanced literature studies and occasional lectures, with recent concentration upon the works of William Faulkner, Henry James, Marcel Proust, James Joyce, Honoré de Balzac, and Charles Dickens. Other long-time interests have included the exploration of generative music sourced from database architecture.

Latest Articles