After you add and configure input, output, transformation, and mapplet objects in a mapping, complete the mapping by linking ports between mapping objects.
The Developer tool creates the connection only when the connection meets link validation and concatenation requirements.
You can leave ports unconnected. The Data Integration Service ignores unconnected ports.
When you link ports between input objects, transformations, mapplets, and output objects, you can create the following types of link:
One to one
One to many
You can manually link ports or link ports automatically.