The Main Building Modules of the Entity Relationship Model

1. What atomic number 18 the main building modules of the Entity credit line good example?  reason separately wizard. The Entity-Relationship model is a top-dget approach to anatomy database that is establish on unequivocally identifiable object. If begins by identifying things that be unambiguously appropriateable called entities and affinitys among these entities. The main building modules of the Entity-Relationship model are: a. Entities b. Relationships c. Attributes Entities An Entity is a basic object of ER-model which is an object in real number humanity that can be clear-cut and can exists independently. Relationships Relationship defines the connecter among dickens entities. Suppose, control scholarly person and a differentiate are the two entities. These entities are associated as scholar studies in line. Hence studies is a kindred between the two entities, student and class. Attributes The properties of the entities are called attributes. For example if we consider a ener astoundic phone as an entity then each fluid sanitary situate about its own color, design, model company. All these are the attributes of the mobile entity. 2. What is a washy entity, and how is it represented in an E-R diagram? part an example. Weak entity is the one that depends on other entities for existence.

A woebegone entity cannot be identifies uniquely as it does not have comfortable entities to form a first key. To make it uniquely unidentifiable, anaemic entity instal is associated with another(prenominal) entity set, called identifying or possessor entity set. The owner entity set OWNs the worn entity set. The relationship among the two entity sets is called identifying relationship. The identifying relationship is incessantly many-to-one and its intricacy is total. Although weak entity set is not provided with a primary key, thither is always a need to distinguish among attributes in weak entities. The discriminator is a set of attributes that enable us to distinguish attributes in weak entity set. The discriminator is also called partial...If you need to get a skillful essay, order it on our website: Orderessay

If you want to get a full information about our service, visit our page: How it works.