Chapter 2: Introduction To Logical Data Modelling
Major Concepts of Logical Data Modelling
- Entity (object): a person, place, thing, object, function which you wish to record facts; we often use a box to represent an entity in logical data modelling
- Relationship: link or association between entities; we often use an arrow to represent a relationship in logical data modelling
- Property: identifications of an entity; an entity has a number of properties.
- Entity set : All members of an entity (e.g, all renters)
- Entity occurrence: One individual in the entity set (e.g., Mr. Smith in the entity Renter)
- Business Rules: Specifications that preserve the integrity of the logical data model by governing which values attributes may assume (Domain business rules, triggering operation)