The Main Building Modules of the Entity Relationship Model

1. What atomic number 18 the main building modules of the Entity affinity flummox?  reason each one. The Entity-Relationship model is a top-down approach to anatomy database that is based on unequivocally placeable object. If begins by identifying things that atomic number 18 uniquely appropriateable called entities and races 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 world that can be discrete and can exists independently. Relationships Relationship defines the association among dickens entities. Suppose, opine scholar and a differentiate are the two entities. These entities are associated as student studies in class. Hence studies is a relationship 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 hire its own color, design, model company. All these are the attributes of the mobile entity. 2. What is a faint 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 basal key. To make it uniquely unidentifiable, anaemic entity instal is associated with another entity set, called identifying or proprietor entity set. The owner entity set OWNs the weak entity set. The relationship among the two entity sets is called identifying relationship. The identifying relationship is continuously 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 motive to get a full essay, order it on our website: OrderCustomPaper.com

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