Database Management Systems
Tutorial Week 9
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The tutorial assessment each week is generally based on your understanding of the week’s course content, your written answers to each week’s tutorial questions, your group interaction in discussing your answers, and your presentation to the class.
You are required to provide written answers to each week’s tutorial questions. The due date for providing answers to each week’s tutorial tasks is by the beginning of your following week’s tutorial session. Make sure to submit your answers to the tutorial questions by its due date electronically using Moodle; and to take with you a printed/hand-written copy of your answers to the next tutorial session. For some questions your tutor may randomly select students to share their answers with the class. For some other questions, your tutor may invite students to discuss their written answers in groups and may ask you to present your group’s collective responses to the class.
Due to some particular circumstances, if you are not able to attend a tutorial session, make sure to:
a) let your tutor know asap the reason(s) you missed the class by email;
b) submit your answers to the tutorial questions by its due date electronically using Moodle.
Before attempting the following tutorial activities, you need to learn this week’s lecture slides. To gain more understanding of the topics covered in this week review Chapters: Chapters: 8.5, 7.2.7, 3.2.2 and 3.3 of your textbook.
ASSESSABLE TASKS OF THE WEEK
Objectives:
Review DDL and DML statements
Investigate views, indexes, data integrity and data security
Activities:
1. Discuss the difference between DDL and DML.
DDL is used to define the structure in the database while DML is used to manipulate or change anything in the database.
2. How would you use SQL to change a table’s structure? What general types of changes are possible? Which commands are used to implement these changes?
3. How can you remove a table using SQL?
DROP TABLE table_name
4. How can you delete all of the data contained within a table? What happens if you do not include a WHERE statement clause?
DELETE FROM table_name
WHERE condition.
If you do not include a WHERE statement clause then you cannot provide any condition.
5. How can VIEWs be used within a database to enhance data privacy? How is a view created?
VIEWs can be used to give permission only to certain people to access certain data or records.
CREATE VIEW view_name AS
SELECT column_name(s)
FROM table_name
WHERE condition
6. How can the value of a piece of data be limited to the values (100, 200, 300)?
7. What does database security refer to?
Database security concerns the use of a broad range of information
