Introduction to MDX: The First Blush
This initial tutorial will introduce the MDX query in its simplest form. We'll take a look at some of the basic keywords, focusing only on simple queries, upon which we will build on in later lessons. Beginning in our first lesson, and throughout most of our series, we will discuss the element(s) of the language under consideration and then perform practice activities, with meaningful examples, to reinforce the concepts we have introduced. In this session, we will explore the rudiments of MDX queries within their simplest contexts (syntax) and introduce terms (semantics) that are applicable as they arise. This lesson will include:
Let's begin by creating and executing a basic MDX query that will provide us a tangible starting point for discussing keywords and components.
- A brief introduction to MDX;
- A discussion of the basic keywords commonly used in MDX;
- A breakdown of a simple MDX query into its component parts;
- Brief comparisons and contrasts of MDX to SQL where useful;
- Other introductory items.
Multidimensional Expressions (MDX) as a Language
MDX emerged circa 1998, when it first began to appear in commercial applications. MDX was created to query OLAP databases, and has become widely adopted within the realm of analytical applications. MDX forms the language component of OLE DB for OLAP, and was designed by Microsoft as a standard for issuing queries to, and exchanging data with, multidimensional data sources. The language is rapidly gaining the support of many OLAP providers, and this trend is expected to continue.
The focus of the MDX Essentials series will be MDX as implemented in MSSQL 2000 Analysis Services. MDX acts in two capacities within Analysis Services: as an expression language that is used to calculate values, and as a query language that is accessed and used by client applications to retrieve data. We will address aspects of both perspectives throughout the series.
Page 3: The Basic MDX Query