it test revision

Question 1

What is a primary key?

Answer 1

A set of values which are unique and cannot be null.

Question 2

What is foreign key?

Answer 2

Is a primary of another table which can be used to find identify the relation between tables, it can also accept null values.

Question 3

What is the main difference between a primary key and foreign key?

Answer 3

A primary key cannot be a null value whereas a foreign key can.

Question 4

List some of the advantages of using a relations database.

Answer 4

Duplicated data is reduced, database space is not wasted.

Question 5

State one manual technique that could be used to ensure that data entry is as accurate as possible?

Question 6

Describe an electronic validation check that could be used to identify as data is entered?

Question 7

What is a flat file data base?

Answer 7

Is a type of data base that store data in a single table

Question 8

What is relation database?

Answer 8

is a collection of data items with predefined relationships between them.