How to bring back the graphical representative of a relationship when the object itself is still there?
If removing the graphical representatives from workspace(WS) and not moving the objects from the model.
To put the removed shortcuts of objects back (when Undo is not possible):
1. Right-click the WS | Complete from Model | Links and Shapes buttons enabled | select the items and confirm OK.
2. If you managed to get back the shapes only (entities), you can simply add relationships this way - right-click the entity and select Fill Parent and Child Objects. Shortcuts of relationships will be added to the WS automatically.