Topic 9b
Writing Database Queries

Learning Objectives

By the end of this topic students should be able to:

• Identify potential redundancy in a dataset and suggest how different relation tables can reduce/eliminate that redundancy.
• Define the concept of a/an [ attribute | relation | tuple ]
• Identify and/or explain the purpose of the [JOIN | PROJECT | SELECT ] operation in database queries.
• Given a description of a database and one or more relational operations, explain the results of the operation(s).

Learning Materials

• Readings
• Section 9.2, pp 478-489 in your book
• Activity
  • Dr. Diesburg made this short video to walk you through getting started.
  • Exploring database queries
    • Link used in the activity

 

Checking for Understanding

Answer the following questions from your textbook. The answers to all Q&E questions are in the back of your book in Appendix F.

• p 489, #1
• p 489, #2
• p 489, #3

Answers & Guidance

The answers to the CFU questions above are provided in the back of the book. The following videos explain how we would arrive at some of those answers.

• CFU, 489, #1
• CFU, 489, #2
• CFU, 489, #3