Referential integrity is important. Whenever a network object refers to another object, WaterSums must ensure that the object really exists. Sometimes, when items are deleted, other items may be depending on them: for example a link will depend on a start node and an end node. Deleting the node requires that any links which depend on the node must also be deleted. WaterSums always checks referential integrity of the network model whenever objects are deleted and if any connected objects are found, a panel is displayed listing the objects. Two lists of objects are displayed in the panel:
- objects that depend on the object(s) to be deleted.
- objects with optional relationships that must be modified so that they no longer depend on the object or objects that are to be deleted.