[Design And Implementation Of A Student Record Prototype System To Generate An Automatic Written Reference Based On Stored Data]

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TABLE OF CONTENTS

CHAPTER 2: LITERATURE REVIEW3

Related Work4

Student Databases and Record Management System6

How a database management system works7

Conceptual Model8

Query language11

Structured Query Language (SQL)12

Integration of Database Schema15

Collaboration And Knowledge Sharing18

REFERENCES20

CHAPTER 2: LITERATURE REVIEW

Conceptual database (DB) schema modelling is mainly based on the Entity-Relationship (ER) model or Unified Modelling Language (UML) class diagrams. Today, many software tools, which rely on these techniques, support (i) the conceptual design of DB schemas, (ii) transformation of conceptual DB schemas into implementation (mainly relational) DB schemas, and (iii) their implementation under different database management systems (DBMSs). In general, there are two basic approaches to a DB schema design: (a) the direct approach, and (b) the approach of a gradual integration of external schemas. In the direct approach, user requirements are analyzed all at once and the whole DB schema is created directly.

This approach may be appropriate in the case of a small DB schema design, but it is inappropriate in the case of a complex DB schema design. The second approach is used when the number and complexity of user requirements exceeds a designer's power of perception. Design of a complex DB schema is based on a gradual integration of external schemas. An external schema is a structure that formally specifies a user's view of a DB schema at the conceptual level. Each transaction program that supports a user request is based on an external schema. After their creation, external schemas are integrated into a conceptual DB schema. Using design methodologies based on the second approach and techniques such as ER modelling or UML, and even the relational data model and an appropriate CASE tool, requires advanced knowledge, skills, and high perception power (Miller, 2002, 33).

Failing to find an appropriate number of designers that possess these properties may lead to a risk of designing a poor quality DB schema. Besides, these methods and techniques are often incomprehensible to end-users. In practice, that may lead to problems in communication and to misunderstandings between designers and end-users. As a rule, misunderstandings result in a poorly designed DB schema, because support of all the specified user requirements is not ensured. Usually, both designers and end-users become aware of that too late, when the DB schema is already implemented. Therefore, it is a challenge to provide an alternative approach, and a CASE tool, which support an automated DB schema design that it is based on concepts end-users are familiar with. A designer who understands and follows the rules for creating design specifications imposed by such a tool would be able to design DB schemas more quickly and easily, even if their complexity extends beyond the limits of usual human perception. A student information system (SIS) is a software application for education establishments to manage student data.

Related Work

Approaches to DB schema design based on the concept of form type have a long tradition. A number of authors, introduced the concept to make ...