Yes, the data source is an easy way of binding that can be configured in the UI Designer and works for Connectors and Business Objects.
If you’re using an SQL connector, you can define your connector, the respective call and the output in the data source. Then, for text/key, define the data source as binding for the property (as you have already done).
Now you still need to tell the app when the Connector/BO should be executed. So, drag and drop the property ‘data source’ to your story in the Process Designer (hover the mouse over the title ‘Data Source’ and you will see an indicator that it can be dragged). A shape will be created automatically that executes the Connector/BO and defines the mapping in the output.
This completes the mapping process.