Creating DFWPs in SharePoint Designer
Using DFWPs, you can connect to those data sources available in the Data Sources left-hand navigation menu in SharePoint Designer, including lists and libraries, external data sources such as database and Representational State Transfer (REST) Web service connections, and linked data sources.
When using DFWPs, you cannot directly connect to External Lists in the Data Sources Picker. However, using the related data sources option in the Data Source Details task pane, you can choose to join an External List to an existing list when then enables you to present the External List in a DFWP. See Chapter 22 for further discussion. See also Chapter 20, “External Content Types and External Lists (BCS),” to ...