You wouldn't have any reason to store data if you didn't want to retrieve it. Relational databases gained wide acceptance principally because they enabled users to query, or access, data easily, without using predefined, rigid navigational paths. Indeed, the acronym SQL stands for Structured Query Language. Microsoft SQL Server provides rich and powerful query capabilities.
In this chapter, we'll examine the SELECT statement and concentrate on features beyond the basics, including NULL, OUTER JOIN, correlated subqueries, aggregates, UNION, and the special CUBE operator. In Chapter 8, we'll see how to modify data. Then in Chapters 9 and 10, we'll build on these topics and explore the constructs and techniques that make Transact-SQL more than simply a query language.