You can use an in-out parameter that holds a variable value that can change each time a task runs to manage incremental data loading.

Add the in-out parameterized field in complex expressions in a mapping if you want to update the parameters when each task runs. The in-out parameter acts like a placeholder for a value that stores a task stage.

Data Integration

evaluates the parameter at runtime based on the specified configuration.

For example, you can use the following parameterized values in an Expression transformation:

SetVariable( $$empID, CONCAT(SUBSTR($$empID,1,3),TO_INTEGER(SUBSTR($$empID,4,2))+1) )

In the example, SetVariable function sets the parameter value each time the

mapping

task runs. You set a default value for the $$empID parameter. You want to update the value of $$empID by one every time the task runs.

The following image shows the logic used in expression transformation to assign value to in-out parameter in the Mapping Designer:

When the task runs, the Secure Agent updates the in-out parameters based on the specified logic in the expression.