1. Introduction to Information Technology
7.6. Databases: Designing a Database
Introduction to Information Technology
INT-1010
Prof C
Luis R Castellanos
1
07.6
Databases:
Designing a Database
2. Introduction to Information Technology
7.6. Databases: Designing a Database
2
Data and
Databases
Before
Databases
Relational
Model
Databases and
security
Database
concepts
Database
design
5. Introduction to Information Technology
7.6. Databases: Designing a Database
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Suppose a university wants to create an information system to track
participation in student clubs.
After interviewing several people, the design team learns that the goal of
implementing the system is to give better insight into how the university funds
clubs.
This will be accomplished by tracking how many members each club has and
how active the clubs are.
From this, the team decides that the system must keep track of the clubs, their
members, and their events.
6. Introduction to Information Technology
7.6. Databases: Designing a Database
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Using this information, the design team determines that the following tables
need to be created:
• Clubs: this will track the club name, the club president, and a short description of the club.
• Students: student name, e-mail, and year of birth.
• Memberships: this table will correlate students with clubs, allowing us to have any given
student join multiple clubs.
• Events: this table will track when the clubs meet and how many students showed up.
7. Introduction to Information Technology
7.6. Databases: Designing a Database
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There are three (3) possible
relationships in DataBase:
8. Introduction to Information Technology
7.6. Databases: Designing a Database
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Now that the design team has determined which tables to create, they need to
define the specific information that each table will hold. This requires
identifying the fields that will be in each table. • Events
• Clubs
• Memberships
• Students
Events Clubs Memberships Students
FName
LName
email
BirthYear
ClubName
President
ShortDesc
EventName
EventDate
Attendance
Every table should have a field in common
with at least one other table!
A primary key must be
selected for each table
StudID
ClubID
EventID
StudID
ClubID
ClubID
9. Introduction to Information Technology
7.6. Databases: Designing a Database
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Here’s what the
database tables
might look like
with some sample
data.
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7.6. Databases: Designing a Database
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Normalization
Database normalization is a process used
to organize a database into tables and
columns. There are three main forms:
first normal form , second normal form,
and third normal form. The main idea is
each table should be about a specific topic
and only supporting topics included.
https://www.essentialsql.com/database-normalization/
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7.6. Databases: Designing a Database
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Reasons for Database
Normalization
There are three main reasons to
normalize a database.
1. to minimize duplicate data
2. to minimize or avoid data
modification issues, and
3. to simplify queries.
https://www.essentialsql.com/database-
normalization/
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7.6. Databases: Designing a Database
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Normal forms
Normal forms are a series of guidelines
for ensuring that databases are
normalized. They are numbered from one
(the lowest form of normalization,
referred to as first normal form or 1NF)
through five (fifth normal form or 5NF).
https://www.lifewire.com/database-
normalization-basics-1019735/
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7.6. Databases: Designing a Database
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1NF (1st Normal Form)
✓ Eliminate duplicative columns from the same table.
✓ Create separate tables for each group of related data
and identify each row with a unique column or set of
columns (the primary key).
2NF (2nd Normal Form)
✓ Remove subsets of data that apply to multiple rows of
a table and place them in separate tables.
✓ Create relationships between these new tables and
their predecessors through the use of foreign keys.
3NF (3rd Normal Form)
✓ Remove columns that are not dependent upon the
primary key.
https://www.lifewire.com/database-
normalization-basics-1019735/
14. Introduction to Information Technology
7.6. Databases: Designing a Database
14
1NF
✓ Eliminate duplicative columns from
the same table.
✓ Create separate tables for each group
of related data and identify each row
with a unique column or set of
columns (the primary key).
15. Introduction to Information Technology
7.6. Databases: Designing a Database
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2NF ✓ Create relationships between
these new tables and their
predecessors through the use
of foreign keys.
✓ Remove subsets of
data that apply to
multiple rows of a
table and place them
in separate tables.
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7.6. Databases: Designing a Database
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3NF
✓ Remove columns that
are not dependent upon
the primary key.
18. Introduction to Information Technology
7.6. Databases: Designing a Database
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• Data are the raw bits and pieces of
information with no context.
• Information is data with context and
has usefulness.
• Knowledge is information (Data in
context) that is analyzed and aggregated
to make decisions.
• A database is a digital collection of
related information to transform data
into information in order to generate
knowledge that can be used for decision
making.
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7.6. Databases: Designing a Database
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• There are three main data types:
structured, unstructured, and semi-
structured.
• Before database systems, computers relied
on a much less elegant and costly approach
to data management called the file-based
system. A file-based system is a collection
of application programs that perform
services for the users wishing to access
information.
• A database management system
(DBMS) is a collection of programs that
enables users to create and maintain
databases and control all access to them.
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7.6. Databases: Designing a Database
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• There are four main distribution
systems for database systems:
Centralized systems, Distributed database
systems, Homogeneous distributed
database systems, and Heterogeneous
distributed database systems.
• A data warehouse is a centralized view
of all data being collected across the
enterprise and provides a means for
determining data that is inconsistent.
• Data mining is the process of analyzing
data to find previously unknown trends,
patterns, and associations in order to
make decisions.
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7.6. Databases: Designing a Database
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• It is the confidentiality, integrity, and availability
(CIA) of the data in a database that needs to be
protected.
• The causes of Database Breaches are Threats
and Vulnerabilities.
• Protect yourself better by a) keeping passwords
to yourself, b) use different passwords for different
accounts, c) use strong passwords, d) check your
credit reports annually, e) control physical access
to your devices, and f) remember to log out or lock
your computer when you are finished using it.
27. Introduction to Information Technology
7.6. Databases: Designing a Database
Textbook
27
https://eng.libretexts.org/Courses/Prince_
Georges_Community_College/INT_1010%
3A_Concepts_in_Computing
Purchase of a book is not
required.
28. Introduction to Information Technology
7.6. Databases: Designing a Database
Professor C
28
castellr@pgcc.edu
eLearning Expert
BS & MS in Systems Engineering
BS & MS in Military Science and Arts
HC Dr in Education
IT Professor | Spanish & GED Instructor
LCINT1010.wordpress.com
Presentation created in 01/2022.
Slides last updated on 05/2023
29. Introduction to Information Technology
7.6. Databases: Designing a Database
Introduction to Information Technology
INT-1010
Prof C
Luis R Castellanos
29
07.6
Databases:
Designing a Database