Database Design

1. Methods of Organizing and
Structuring Data

2.  data is the vital ingredient or raw material that
is processed in an information system.
 Structure of data can be examined from a
technical or logical viewpoint.
 determining the structure of data involves
identifying how the individual items of data must
be arranged.

3. Records
 data which is used by business and government
typically has the structure of a table.
 consider the problem of storing the following data
about each student in your class:
i. Name
ii. age
iii. birth date
iv. address
v. phone number

4. Table of data
Identification Name Age Address Date of birth Phone
Number Number
A10-12586 Roxane 14 10 Black St 07/08/97 661-78-22
La’O Caulfield
3162

5.  In the example given you could organize the data in a
sorted order and distinguish each record by using ‘name’
field.
Each field has two important attributes which must be
carefully chosen.
1. each field must be given a set
width
2. the type of each field must be
determined

6. Fields Type Width Justification
Name C (Characters) 20 Worse case
lenght
Address C 30 Fit all data
Date of birth N (Numeric) 6 Can store
20.10.61
Phone C 12 Phone numbers
as characters

7. Relational Data
Structures
 Many organizational problems can be easily
solved by storing data in more than one table or
flat file.

8. Context Diagram
Patrons
Management
System
Book file
Patron file
Books
Loan file

9.  A relational database table or file needs to be designed in
the same way as for a flat file. This means that we need to
develop a data dictionary:
Data dictionary-customers
Field Name Data type Width Validation rule
Customer ID Number > 0 and < 20 000
Customer name Character 30 Not blank
Address Character 30
Suburb Character 20 Not blank
Postcode Number >1000 and
<10 000
Phone number character 15

10. Data structure-books
Field name Data type Width Validation Rule
Book ID Number >1 and <10 000
Title Character 60 Not blank
Rental Currency >0 and <20
Rental period Number >0 and <50
Date loaned Date
Customer ID Number >0 and <10 000

11.  one patron can borrow many books; this is called one
to many relationship.
However, a single video can be relate to only one
customer; this is referred to as a one to one
relationship.

12. Relationships
Books
Customer Psychology
Roxane English
Algebra
One to many relationship
Book
Customer
Psychology
One to one relationship

13. Design strategy for
WWW documents
When designing the basic data structure for a World Wide
Web document you should:
 outline the overall block structure
 outline each sub-documentary structure
 outline each sub-secondary structure.

14. Data structure and
design of a multimedia
presentation
 HTML and Internet-enabled documents are examples of multimedia
documents.
Multimedia documents have the capacity to present information in a
variety of formats: text, hypertext, sound, graphics and video.

15. Formats of Multimedia Presentation can be:
Simple Multimedia Presentation
 In the past, such presentation would typically have
been done with slides or an overhead projector.
 data structure of a standard presentation takes the
format of a linear sequence of slides.
 the most common software used for this is
powerpoint.

16. Complex Multimedia presentation:
You will probably have seen many examples of World
Wide Web documents.
 many of these contain the characteristics of a simple,
linear multimedia design.


17. Important data
structure design
consideration
1. Structure of a Graphics File – a graphics file is a digitised version
of an existing image or one that has been designed using graphic
design doftware.
 size of the image
 location on screen
 resolution required
 colour required
 storage format
 display mode (for example: internet,word-
processing,database).

18. 2. Testing and Validating Data
 Validation refers to the checking of data to ensure that
it is reasonable.
 Testing of a solution refers to the process of verifying
that a solution produces the correct results after data
has been processed.

19. Validation:
Input
Name VALIDATE
Date of Birth • Date of birth
Age • Age
Sex • Sex
Write data to file on disk
OK
Record

20. Prepared by:
Anna Roxane La’O