What is SQL?
To import data from another sql database, you need to add the server as a Datasource Server first. Select Show Datasource Servers in the Import Browser and right click the free area and select Add Datasource Server.
You can add a Datasource Server the same way, you added the Staging Server.
To start the SQLImport, right click the project in the Import Browser you want to upload data to and select Import Data -> Import SQL.