Developer Workflow Guide

Back Next

Variable Names in Expressions and Strings

When you use a workflow variable name in an expression or a string field, you can select the name from the

Inputs

tab or you can type the name using the required syntax.

The following table shows the required syntax for workflow variable names in expression and string fields:

Field	Syntax	Example
Expression in a conditional sequence flow or in an Assignment task	$var:<variable_name> for user-defined variables $var:sys.<variable_name> for system variables	For example, you create a workflow variable named CommandExitCode and assign the exit code output value for a Command task to the variable. You create the following expression in the conditional sequence flow that connects the Command task to a Mapping task: $var:CommandExitCode = 0 The Data Integration Service evaluates the condition and runs the Mapping task if the previous Command task returned 0 in the exit code which indicates that the command succeeded.
String field for a Command or Notification task	${var:<variable_name>} for user-defined variables ${var:sys.<variable_name>} for system variables	When you enter a variable name in a string field for a Command or Notification task, you must include brackets around the variable name. For example, you create a workflow variable named MappingErrorRows and assign the number of error rows output value for a Mapping task to the variable. You enter the following text in the body of a Notification task: Mapping failed to write ${var:MappingErrorRows} rows to the target.