6. Elements
Elements are used to define the characteristics or attributes of an entity.
For example, a Customer entity might have elements of Customer Name, Customer Code, Credit Limit etc.
Elements can be created:
- within an entity, or
- as unattached elements that can be attached to an entity at a later stage.
Elements in the Logical Modeler follow the rules of Chen E-R Data Models. For instance, the following rules apply:
- An entity may have only one identifying element.
- An entity can inherit elements as the result of relationships with other entities.
- An element may be defined only once to a model.
- If an element exists in more than one entity, it must do so by means of a relationship.
This information is described in: