About the Series ...
This is the seventeenth article of the series, MDX Essentials. The series is designed to provide hands-on application of the fundamentals of the Multidimensional Expressions (MDX) language, with each tutorial progressively adding features designed to meet specific real-world needs.
For more information about the series in general, as well as the software and systems requirements needed for getting the most out of the lessons included, please see the first article, MDX at First Glance: Introduction to MDX Essentials.
Note: Service Pack 3 updates are assumed for MSSQL Server 2000, MSSQL Server 2000 Analysis Services, and the related Books Online and Samples.
What We Accomplished in our Last Article
In the last article of the series, Basic Set Functions: The Filter() Function, we explored the useful Filter() function. We learned that the purpose of the function is to allow us to filter out parts of a set that we do not need, and to return a subset of a larger specified set as a result. We discussed Filter() in general, along with the capabilities it affords us within MDX, emphasizing its value in helping us to attain efficiency and precision in our MDX queries.
In addition to discussing the purpose and operation of the Filter() function, we examined the syntax involved in its use. We then illustrated its application in practice exercises. Finally, we provided, as a complement to our hands-on exposure to the Filter() function, a brief discussion of the MDX results we obtained.
Microsoft Analysis Services ("MSAS"), as most of us know, leads the enterprise business intelligence arena with its rich set of mathematical and analytical tools. Most of these tools rely upon functions based in the MDX query language. MDX is integrated not only within MSAS, but also throughout the entire Microsoft Business Intelligence Platform in applications that include Data Mining and Reporting Services. This integration provides a distinct advantage for the platform over the offerings of other vendors, and, particularly in the case of numerical functions, allows for easy, consistent application of built-in logic.
In this lesson, we will extend our attention from the purely set-related functions upon which we have concentrated in the last several articles; we will focus on a numerical function, Count(), specifically as it is applied to sets. We will discuss the straightforward purpose of the function, to return the number of cells in a specified set, and then expose approaches within the syntax for handling the inclusion or exclusion of empty cells within the returned result.
Along with an introduction to the Count() function, this lesson will include:
- an examination of the syntaxes surrounding the function;
- illustrative examples of the uses of the function in practice exercises;
- a brief discussion of the MDX results we obtain in the practice examples.