Chapter 5. Computing Aggregates

After completing this chapter, you will be able to:

• Use aggregate functions in your applications to return totals and other summarizations from your data

• Use these functions to improve performance and enhance features of your applications

• Use CLR (common language runtime) aggregate functions to perform specialized calculations

In Part I of this book you learned how to design and build your database, to secure your database against unauthorized use and against unforeseen data loss, and to transfer your data to other locations. In Part II we'll look at how to manipulate the data in your database, starting in this chapter with how to compute totals and other summary information about data in a table.

Read this chapter with SQL Server Management Studio in front of you. Open a New Query window connected to your SQL Server and select AdventureWorks as your connected database.

As you read through the examples presented in this chapter, experiment with your own combinations and ideas. Aggregate functions perform read operations only, so there's no chance of damaging your database by trying something new.