Welcome to ecourse.org: the Information Infrastructure for Education in the information age! This system allows instructors from any school or college (including home schools and training programs) to teach either onsite or online courses . It allows students to manage all their ongoing school works and past academic records at one location.
Our mission is to redefine the model of learning and re-engineer its process by providing innovative administrative and instructional technologies. Click here for our beliefs.
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Could another species someday replace us as Earth's dominant intelligent life and, if so, which species?
(324 Week 3 Outline) (by Liping Liu) Review on Business Data Modeling:
How do you handle composite attributes?
Verb describing relationships and Need to Track Related Records
data on actions may be recorded and so to turn action verbs into objects
Customer buys products
Student reserve books
Orders contains products, direct or indirect relationships?
Employees balance inventories, direct or indirect relationships?
Employee manage accounts
Doctors prescribe tests
Professors teach students
Customers wish-list products
Customers rate Products
Professors advise Students
Patrons checkout Books
Lecture 1: Advanced Entities and Relationships
1) What if relationships have data or attributes? (Chapter 3 of LIU)
Associative Entities or Gerunds: where to keep students grades, Where do you store data on whether a payment is late or not? Bank employees may set up or modify accounts... more >>
(641 Week 1 Outline) (by Liping Liu) Concept of Database:
Database is a set of records well organized using a particular logical data model
Records: A records is an array of observed characteristics (or attributes) on one object (entity)
Well Organized: 1) related records are connected; 2) no unnecessary redundancy
Logical Data Models: Hierarchical, Network, Relational
Database Development Process
Data Modeling: Entity, Attribute, relationships
Database Implementation: DBMS
CASE Tool: Oracle Data Modeler
Terminology Confusion: logical model = conceptual model, relational model = logical model
How to draw entities, create attributes, and refine relationships using Oracle Data Modeler
Data Modeling: Identify Objects, Attributes, and Relationships
Identify Objects: (1) objects can be tangible such as a customer or intangible such as an account or meeting; (2) objects must be observable at an instant in time; (3) objects must have multiple attributes (or dimensions) to be observed... more >>
This system is designed and developed by Professor Liping Liu with financial support from Southern Illinois University at Carbondale. It evolved from a prior version called CourseWeb (for courses prior to Year 2000) and UXTEND.COM and www.e-course.org.
