Beginning T-SQL with Microsoft® SQL Server® 2005 and 2008

Chapter 5. Data Retrieval

In Chapter 4, you learned that as the SQL language has evolved, it has expanded to add more capabilities. In this chapter you learn the fundamentals of the Data Manipulation Language (DML) aspects of T-SQL as they relate to retrieving data. Topics include filtering results with the WHERE clause, limiting results to specific table attributes, and ordering results to conform to business requirements. Subsequent chapters build on these concepts as you learn about more advanced implementations of these DML components.

Storage and Retrieval

I'm not a particularly organized person by nature. When I am done using an item, my first impulse is to toss it on my dresser or a table. The workbench in my garage hasn't seen the light of day for several months. I tell you this so you can understand my deep appreciation for the orderliness of a relational database. Perhaps this is the element in my life that helps me compensate for the lack of order in other areas. I also love containers of all kinds. The cool thing about having containers is that when you need to put something away, there's always a place for it, but when it comes time to find it, that's often another story.

Retrieving data through queries is really about finding stuff. SQL queries are used to reach into the database and pull out useful information; sometimes you need to get all of the details and sometimes you need only a subset of data based on common characteristics. At times, the value or values you'll ...