4.10 Fundamentals of Databases

Question 1

Define an attribute/field

Answer 1

An individual fact, detail or characteristic of an entity

Question 2

Define Database

Answer 2

An organised collection of related data/information

Question 3

Define Entity

Answer 3

A thing, object or attribute about data that can be collected

Question 4

What is a Flat-file Database

Answer 4

A database containing a single table

Question 5

Define Primary Key

Answer 5

A unique piece of information within a table used to identify a record

Question 6

Define Record

Answer 6

A collection of fields that refer to the same entity (usually a row in a table)

Question 7

Define Foreign Key

Answer 7

A field in the table which contains the value of a primary key in another table (in essence linking 2 tables together).

Question 8

Define (Data) Redundancy

Answer 8

The duplication of data within a database

Question 9

What is a Relational Database

Answer 9

A database with multiple linked tables

Question 10

Define a table

Answer 10

A collection of related data

Question 11

Describe the problem with redundancy in FFD

Answer 11

• If a data redundant field has to be changed, all of the fields which contain the same value must be modified, this makes the table more prone to error and so has less data integrity

Question 12

Explain the 3 Entity Relationships

Answer 12

1 - one-to-one (1:1) where one instance of an entity is associated to one instance of an entity
1 - one-to-many (1:N) where one instance of an entity is associated to more than one instance of an entity
1 - many-to-many (M:N) where more than one instance of an entity is associated to more than one instance of an entity