Delete Rules
An important relationship setting to be aware of is Delete Rule. When an object is deleted, this setting determines what happens to related objects, as detailed here:
The Nullify delete rule is a good default for most situations. When an object is deleted and this rule is in place, related objects nil out their relationship to the deleted object. For example, assume a unit object named Kg is related to some item objects. If a Nullify delete rule was set on the items relationship and the Kg unit object was deleted, the related item objects would set their unit property to nil.
The Cascade delete rule propagates deletions through ...
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