Summary

Expressions are one of the major components that make SSRS flexible, yet powerful. Using them, you can make decisions at runtime and base decisions on the data being returned. Expressions are derivatives of VB.NET, or they can be constants.

Expressions contain constants, variables , operators, collection members , and functions.

There are five major collections: Globals , Fields , Parameters , ReportItems , and User .

By combining these collections with either aggregate functions or any other kind of function, you can make powerful expressions that help to add a level of dynamism to reports .