This shows a variable number of "fields" for each "record".
Draw new links by dragging from the background of any field. Reconnect a selected link by dragging its diamond-shaped handle. The "record" Nodes are not movable or copyable or deletable.
The model data, automatically updated after each change or undo or redo:
See also the variation on this sample with selectable fields in the record nodes: Selectable Fields.