In the previous lesson, you added source and target definitions to the repository. You also generated and ran the SQL code to create target tables.
The next step is to create a mapping to depict the flow of data between sources and targets. For this step, you create a pass-through mapping. A pass-through mapping inserts all the source rows into the target.
To create and edit mappings, you use the Mapping Designer tool in the Designer. You add transformations to a mapping that depict how the Integration Service extracts and transforms data before it loads a target.
The following figure shows a mapping between a source and a target with a Source Qualifier transformation:
The source qualifier represents the rows that the Integration Service reads from the source when it runs a session.
If you examine the mapping, you see that data flows from the source definition to the Source Qualifier transformation to the target definition through a series of input and output ports.
The source provides information, so it contains only output ports, one for each column. Each output port is connected to a corresponding input port in the Source Qualifier transformation. The Source Qualifier transformation contains both input and output ports. The target contains input ports.
When you design mappings that contain different types of transformations, you can configure transformation ports as inputs, outputs, or both. You can rename ports and change the datatypes.