Unit 2: Database Architecture and Date Languages
In order to properly create and then manage a database, we need to have a thorough understanding of the data it holds. Because data can be seen from different levels, we will introduce different data models and learn how to apply them in order to describe the structure of the database, thereby providing a "view" of the database for the different types of users introduced in the previous section.
Completing this unit should take you approximately 2 hours.
2.1: Database and Three-Schema Architecture
Read this chapter, which is the culmination of many years of developing online database resources. It includes notes as well as quizzes and an interactive SQL practice environment.
Read this page.
2.2: Tables, Views, and Indexes
Read this article.
This video explains the concepts of a relational database using Microsoft Excel. A "primary key" is a special type of index - one that is unique and the main or primary value used to locate an entry in a database.
This lecture explains the basic concepts of relational databases, including tables, columns, primary keys, foreign keys, and referential integrity. It then illustrates them using a customer order database. In the latter part of the lecture, Zellers introduces Microsoft Access for implementing a relational database.