Week 4 - RELATIONAL DATA MODEL

In relational data model, the total number of rows can be identified as ______________________ .

• Cardinality

• Degree

• Attribute

• Entity

Identify the total number of attributes in a relational data model.

• Tuple

• Entity

• Degree

• Cardinality

Identify the candidate key.

• W

• X

• Y

• Z

An attribute whose value is calculated (derived) from other attributes. Choose the correct attributes based on the information given.

• Registration Number

• IC Number

• Certificates

• Date of Birth

If related data exists in more than one table, they can be joined by using the Primary Key link to the same key in the other table. Identify this key.

• Foreign Key

• Primary Key

• Candidate Key

• Composite Key

In relational data model, the total number of attributes can be identified as ______________________ .

• Cardinality

• Degree

• Tuple

• Entity

Based on the figure above, identify the number of tuples that will be returned by the following relational algebra query :  $\sigma\$ Type = 'Saving' (Account)

• 2

• 3

• 6

• 0

Base on the table given, identify output that will be produced when, σ _{Salary > 3000 ˅ City = ‘Batu Pahat’} (WORKER).

• 
• 
• 
• 

What is data types?

• It specifies what type of data is expected inside of each column in a table (ef. number, date, string)
• It specifies how many tables you will create when you convert your Entity Relations Model to a Logical Data Model
• It specifies the database-name
• It counts how many attributes you have

What does the data-type INT contain

• Whole numbers
• Decimal numbers
• Characters
• Date