IB A3

Question 1

What is a database?

Answer 1

A database refers to an organized collection of structured information or data that can be accessed in different ways.

Question 2

What is a table?

Answer 2

structure
of rows and columns
for storing a group of
similar data.

Question 3

What is an entity?

Answer 3

a living or
non-living thing that can
have data stored about
it that can be described

Question 4

What is a tuple/record?

Answer 4

one instance of an entity; a row in
a table.

Question 5

What is an attribute/field?

Answer 5

attribute: a data
item or a characteristic
of an entity; a column in
a table.

Question 6

What is the primary key?

Answer 6

Primary key: a field
that uniquely identifies a
record in a table.

Question 7

What is the foreign key?

Answer 7

Foreign key: an
attribute in a table that
refers to the primary key
in another table.

Question 8

What is the composite key?

Answer 8

Composite key: a set
of attributes that form a
primary key.

Question 9

What is a relationship?

Answer 9

4 Relationship: a
relation established
between different
tables, where the
foreign key in one table
refers to the primary key
in another table

Question 10

What are the different types of relationships?

Answer 10

one-to-one (1:1)
one-to-many (1:m)
many-to-one (m:1)
many-to-many (m:m).

Question 11

How does a one-to-one relationship work?

Answer 11

When there is a one-to-one relationship between two tables, that means that one record in a
table is associated with exactly one record in another table: the primary key corresponds to
one or no data in another table. For example, each staff member of a school has one single
staff ID; each country has exactly one capital city; or a user on a social media platform has a
single user profile. Those are very rare types of relationships, which you will not frequently
encounter when dealing with databases.

Question 12

How does a One-to-many relationship work?

Answer 12

This is a frequently used type of relationship, and it refers to one record in a table being
associated with one or more records in another table: the toreign key of one table references
the primary key of another table. Examples of one-to-many relationships are where one teacher
teaches many subjects; one tourist visits many countries; one person owns many properties;
one person has many bank accounts.