- About the Series
- Introducing MDX Queries
- Key Concepts and Terminology
- Introducing Sets
- Understanding Metadata
- Working with MDX Queries
- Working with Member Sets
- Specifying Members in a Set
- Using the CrossJoin Function to Combine Multidimensional Sets
- Looking Ahead to Calculated Members
- Next in This Series
Introducing MDX Queries
The first order of business is to gain a good understanding of MDX query statements, and how they differ from the multidimensional expressions used earlier in this series.
Remember that an expression calculates a single value. You can use Excel PivotTable reports and Office PivotTable lists to create multidimensional expression statements to retrieve values from an OLAP data source. In contrast, a query is used to extract multiple values from a cube. Queries underlie the reporting that you might do in the PivotTable components, and are often largely invisible when developing reports visually with these and other tools.
For details on using Office and SQL Server 2000 OLAP, see my other InformIT series, "Integrating Microsoft SQL Server 2000 OLAP and Microsoft Office."
Often it's useful to juxtapose expressions and the values they retrieve, to obtain a multidimensional value for analysis. This tutorial and others to follow explain how to create MDX queries and the underlying query components that are generated in the background when creating MDX expressions with visual tools. Knowing how to create queries will equip you to retrieve values to support the reporting requirements of information consumers. You'll also come to understand how to maintain those queries to meet changing demands, through the precise specification of dimensional criteria.