If the Designer detects an error when you try to link ports between two mapping objects, it displays a symbol indicating that you cannot link the ports.

Follow logic of data flow in the mapping. You can link the following types of ports:

You must link at least one port of an input group to an upstream transformation.

You must link at least one port of an output group to a downstream transformation.

You can link ports from one active transformation or one output group of an active transformation to an input group of another transformation.

You cannot connect an active transformation and a passive transformation to the same downstream transformation or transformation input group.

You cannot connect more than one active transformation to the same downstream transformation or transformation input group.

You can connect any number of passive transformations to the same downstream transformation, transformation input group, or target.

You can link ports from two output groups in the same transformation to one Joiner transformation configured for sorted data if the data from both output groups is sorted.

You can only link ports with compatible datatypes. The Designer verifies that it can map between the two datatypes before linking them. The Integration Service cannot transform data between ports with incompatible datatypes. While the datatypes do not have to be identical, they do have to be compatible, such as Char and Varchar.

You must connect a source definition to a source qualifier only. You then link the source qualifier to targets or other transformations.

You can link columns to a target definition in a mapping, but you cannot copy columns into a target definition in a mapping. Use the Target Designer to add columns to a target definition.

The Designer marks some mappings invalid if the mapping violates data flow validation.