About the Main Windows and Wizards - SAS Data Integration Studio 3.3 User's Guide - page 16

Expression Builder Window

Use the Expression Builder to create SAS expressions that aggregate columns,
perform conditional processing, and perform other tasks. For example, the following
display shows an expression that sums the values in a column named
Total_Retail_Price.

Display 3.2 Expression Builder Window with a SUM Expression

The Expression Builder is displayed from tabs in the property windows of many SAS
Data Integration Studio transformations. For an example of how the Expression
Builder can be displayed and used in the context of a job, see “Change One Column to a
Calculated Column” on page 157.
The Expression Builder is used to add or update expressions in SAS, SQL, or MDX.
The expression can transform columns, provide conditional processing, calculate new
values, and assign new values. The expressions specify the following elements, among
others:
￿ column names
￿ SAS functions
￿ constants (fixed values)
￿ sequences of operands (something to be operated on like a column name or a
constant) and operators, which form a set of instructions to produce a value
An expression can be as simple as a constant or a column name, or an expression can
contain multiple operations connected by logical operators. For example, an expression
to define how the values for the column COMMISSION are calculated could be amount