Entities use identifiers while tables use keys.

More Questions from Data Modeling with ER Model

• 1:1, 1:N and N:M relationships are also known as HAS-A relationships.
• An attribute describes the entity's characteristics.
• The degree of a relationship refers to the number of entity classes in the relationship.
• An identifier determines the type of relationship that an entity has.
• A recursive relationship is a relationship between an archetype and an instance of that archetype.
• A subtype entity is a special case of another entity called a supertype entity.
• An entity class is a collection of entities and is described by the structure of the entities in that class.
• A minimum cardinality is the minimum number of entity instances that may participate in a relationship instance.

Discussion & Comments