You can place conditions on the links you draw between variables. At run time, Integration Server evaluates the condition and executes the link (copies the value) only if the condition evaluates to true.

A condition consists of one or more expressions that you write using the syntax that Designer provides. An expression can check for the existence of a variable in the pipeline, check for the value of a variable, or compare a variable to another variable. For example, in the following service, you might want to link the BuyersTotal variable in Pipeline In to the OrderTotal variable in Service In only if the BuyersTotal has a value that is not null. After you link two variables, you would edit the properties and add the condition that needs to be true.

Designer uses a blue link in the Pipeline view to indicate that properties (that is, conditions or index values for arrays) have been applied to a link between variables.