tailieunhanh - Lecture Enterprise information systems: A pattern-based approach (3/e): Chapter 6 - Cheryl Dunn, J. Owen Cherrington, Anita Hollander

Chapter 6 - Relational database design: Converting conceptual models to relational databases. The primary objective of this chapter is to describe a procedure for converting a conceptual business process level REA model into a logical relational database model and then into a physical Microsoft Access database implementation. This process involves a relatively straightforward set of rules that could even be programmed as an algorithm so that a computer could accomplish the conversion. This chapter also discusses data entry issues. | Chapter 6 Relational Database Design: Converting Conceptual Models to Relational Databases Chapter Learning Objectives Convert a conceptual business process level REA model into a logical relational model Convert a logical relational model into a physical implementation using Microsoft Access Explain the difference between conceptual, logical, and physical database models Enter transaction data into a relational database Interpret a physical database implementation in Microsoft Access to determine what must have been the underlying logical model Interpret a logical relational model to determine what the underlying conceptual model must have been Recognize and implement various application level controls to facilitate the integrity of data entered into a relational database 6- Database Model Levels A Conceptual model represents reality in an abstracted form that can be used in developing an information system in a wide variety of formats (. relational, object-oriented, flat-file, etc.) It is hardware and software independent It is independent of any logical model type A Logical model represents reality in the format required by a particular database model (. relational or object-oriented) Is still hardware and software independent Depends on the chosen logical model type A Physical model is created specifically for a particular database software package Is dependent on hardware, software, and on the chosen logical model type 6- Relational Database Model The relational model is a type of logical database model that was conceived by . Codd in 1969 The relational model is based on set theory and predicate logic It is well formalized, so its behavior is predictable A relational database consists of tables (relations) that are linked together via the use of primary and foreign keys A FOREIGN KEY in a table is a primary key from a different table that has been posted into the table to create a link between the two tables 6- Relational Database Model . | Chapter 6 Relational Database Design: Converting Conceptual Models to Relational Databases Chapter Learning Objectives Convert a conceptual business process level REA model into a logical relational model Convert a logical relational model into a physical implementation using Microsoft Access Explain the difference between conceptual, logical, and physical database models Enter transaction data into a relational database Interpret a physical database implementation in Microsoft Access to determine what must have been the underlying logical model Interpret a logical relational model to determine what the underlying conceptual model must have been Recognize and implement various application level controls to facilitate the integrity of data entered into a relational database 6- Database Model Levels A Conceptual model represents reality in an abstracted form that can be used in developing an information system in a wide variety of formats (. relational, object-oriented, .