Chapter 6

Using Variables, Parameters, and Expressions

WHAT’S IN THIS CHAPTER?

• Reviewing variables, parameters, and expressions
• Using data types for variables and parameters
• Creating variables and parameters
• Expression syntax and usage
• Expression examples

If you have used SSIS packages for any involved ETL processes, you have inevitably encountered the need for dynamic capabilities. A dynamic package can reconfigure itself at runtime to do things like run certain steps conditionally, create a series of auto-generated filenames for export, or retrieve and set send-to addresses on an alert e-mail from a data table. Because dynamic changes are fairly common occurrences, developers and architects have turned to expressions as they begin rolling out SSIS projects in their development shops.