013BSCCSIT001Aabhash Dhakal1.ER diagram with case study2.DESIGNDatabase systems are designed to manage large bodies of information. Theselarge bodies of information do not exist in isolation. They are part of theoperation of some enterprise whose end product may be information fromthe database or may be some device or service for which the database playsonly a supporting role. The design of any information system is divided intotwo tasks, first the database design and secondly the functional design or asit is sometimes known, operational design.2.1 Database DesignIn database design, the necessary structure and organization of the dataare established.Fig. Phases of database design
013BSCCSIT001Aabhash Dhakal2.1.1Conceptual DesignThe purpose of conceptual design is to represent the informalrequirements of an application in terms of a formal and completedescription, but independent of the criteria for representation usedin database management systems.The product of this phase is called the conceptual schema.Conceptual models allow the description of the organization ofdata at a high level of abstraction, without taking into account theimplementation aspects.2.1.2Logical DesignThis consists of the translation of the conceptual schema defined inthe conceptual phase, into the data model adopted by the databasemanagement system available.