Creating Entity-relationship Diagrams (E-R Diagrams)
Last semester for my introductory GIS class, part of a laboratory exercise is on creating E-R Diagrams which for me is a simple graph of the relationships between different objects within an interface. In programming, it is much like the UML (Unified Modeling Language) class diagrams that we are making before proceeding to the actual coding. E-R diagram A data model, which is a high level description of the available data, is needed in storing relevant information in a database. In designing databases, there should be a conceptual and the physical phase. The creation of E-R (entity-relationship) diagrams belong to the conceptual phase. The E-R diagram serves as the blueprint before creating a database. There are things such as entity sets within an E-R Diagram 1. Entity – person, place, object, event, concept. representation in the E-R diagram - table in the database shape in the E-R diagram - RECTANGLE 2. Entity sets – collection of similar entities (sa...