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?
(641 Week 3 Outline) (by Liping Liu) Review: Course and Sections (why splits), Course and Prerequisites (Two entities or one?), Grade (where to store it), minimum grade required for prerequisites
Lecture 1: Forward Engineering: ERD to Relational Model: (Remember these rules, Chapter 6 of LIU)
Each entity set is converted into a table with its attributes as the columns of the table
Depending on the mapping cardinality, you modify the tables to make them related
If the relationship is 1:m or m:1, you put the primary key of the table for one-side entity set into the table for the many-side entity set
If the relationship is m:m, you build a junction table which has the primary keys of both entity sets as columns
If the relationship is 1:1, you can put the primary key of one entity set into the table for another entity set... more >>
(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 >>
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.
