# MDX Essentials : MDX Operators: The Basics

January 28, 2003

Author Bill Pearson continues his MDX Essentials Series with a discussion of three basic operators: Braces, Comma, and Colon. After a brief review of each, we examine the syntax involved in putting it into action, and the practical use of the operator in helping us to achieve our query objectives.

### About the Series ...

This is the third article of the series, MDX Essentials. The primary focus of this series is an introduction to the MDX language. 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.

### What We Accomplished in our Last Article

In the second article of the series, we introduced the MDX data model, together with its most basic components, tuples, axes, and sets. We focused on the composition and common uses of tuples, axes and sets, and provided hands-on exposure to these building blocks. After discussing each of the three components, we emphasized rules of syntax that related to each, providing a foundation to build upon throughout the rest of the series. Finally, we worked practice exercises to demonstrate tangible results, and to reinforce our discussions with examples.

In this lesson, MDX Operators: The Basics, we will introduce additional ways to construct tuples and sets, taking up first the most basic of the components involved. The operators we explore in this lesson will include curled braces "{}", commas "," and colons ":". With each of the operators, we will illustrate the uses and options that are available to us in constructing basic MDX queries.

### Introduction to Basic Operators

In this article, we will introduce basic components involved in the building of tuples and sets. We will focus on the composition of these important building blocks, and provide hands-on exposure to their use in simple expressions that we will run to view their output. Rules of syntax will be emphasized, the aggregate body of which will provide a basis for more complex query building as we progress through the series.

This lesson will include:

• A brief discussion of curled braces "{}", commas "," and colons ":";

• A examination of the MDX query results we obtain in examples that use the operators under consideration.

Let's begin by discussing the most common of the MDX operators, and some of the ways that we can call upon them in the development of expressions that we can use in standalone fashion, or that we might use in more sophisticated expressions or queries, to achieve our ends.

### Basic Operators: Curled Braces, Commas and Colons

We previewed the use of curled braces and commas in our last session, within our overview of sets, and in other passages of the lesson. Curled (or "curly," depending upon whom you ask) braces must be used in some situations, and simply can be used in others. We will touch on these, as well as upon the use of curled braces to set apart set expressions consistently, to make learning MDX easier. As we stated in our last section, MDX is similar to other programming languages in its uses of various operators; one of those uses is to identify sets. Among these operators are the colon and comma (used as separators between members within sets), which, along with curled braces, will form the subjects of this lesson.