Transcript Data Elements and Tables

Chapter 7
Data Elements and Tables
IT Key Ideas, Dynamic Database Systems, 2002
Databases
page 75
Table
A table or file is a collection of related data. For
example, a book with pages listing the details of all
the members in a club.
Record
A record, card or form, is a collection of data for one
individual entity. Each record contains the same type
of data. For example, the information about a single
member is a record (one line of the membership
page).
Field
A field is one element of data, one single
attributes of the entity. For example, the
member’s date of birth is a single element of
data.
IT Key Ideas, Dynamic Database Systems, 2002
Table
Surname
Burrell
Bettridge
Collins
Harding
Lucas
Quintrell
Robertson
Rogers
Washington
Zengerer
Given Name
Patrick
Shantala
Joanna
Barry
Karina
Holly
May
Romany
Leandra
Sibyl
of members
Address
7 Barker Rd
39 Heath Rd
16 Penworth Lane
35 Princeton Tce
30 Holldsworth St
39 Bellington St
8 Grote Rd
26 Young Rd
7 Sherriffs Rd
18 Junkett St
IT Key Ideas, Dynamic Database Systems, 2002
Suburb
Lurnea
Ermington
Elanora
Ermington
Elanora
Lurnea
Lurnea
Ermington
Elanora
Elanora
Phone
82762798
82124396
82938757
82947412
83844217
82637726
82683139
82689936
82705928
82700958
Title
Mr
Mrs
Mrs
Mrs
Mrs
Mrs
Mrs
Mrs
Mrs
Mrs
Record
LK
Lucas
a member
Karina
30 Holldsworth St
IT Key Ideas, Dynamic Database Systems, 2002
Elanora
83844217 Mrs
Data
Harding
Lucas
Quintrell
a word, character
Barry
Karina
Holly
IT Key Ideas, Dynamic Database Systems, 2002
35 Princeton Tce
30 Holldsworth
39 Bellington St
Database Management Systems
A relational database management system
consists of a number of tables. Each table stores
data about a particular entity. The tables are
related through common fields creating a system,
from which data can be retrieved quickly and
efficiently.
Data Elements
• a person’s surname
• a person’s hair colour
• a person’s date of birth
• a car’s registration number
• a teacher’s qualification
• a student’s semester grade
• a venue’s seat number
• a venue’s seating capacity
IT Key Ideas, Dynamic Database Systems, 2002
page 75
Calculated Data Elements
page 75
• a student’s percentage (on a test)
• a club’s number of financial members
• a business’s profit
• in a theatre the seats available
IT Key Ideas, Dynamic Database Systems, 2002
Data Elements
page 76
suggest at least six elements of data that would be stored
IT Key Ideas, Dynamic Database Systems, 2002
Data Elements
page 77
Exercise 7.1
IT Key Ideas, Dynamic Database Systems, 2002
Stored or Calculated Fields
Data Element
Lesson Date
Lesson Time
Instructor
Swimmer
Number of swimmers
Date of Birth
Group
Number of lessons
Fees paid
Stored or Calculated?
stored
stored
stored
stored
calculated
stored
stored
calculated
calculated
IT Key Ideas, Dynamic Database Systems, 2002
Data Elements & Tables
page 79
suggest at least six elements of data that would be stored in a
Stores table
Store Number
Shop Number
Address
Suburb
Phone Number
Fax Number
Manager
IT Key Ideas, Dynamic Database Systems, 2002
Data Elements
page 80
Exercise 7.3
IT Key Ideas, Dynamic Database Systems, 2002
Data Elements
page 81
Exercise 7.4
IT Key Ideas, Dynamic Database Systems, 2002
Grouping
Data
Elements
suggest at
least ten
fields and
group them
page 82
IT Key Ideas, Dynamic Database
Systems, 2002
Registration
Surname
Registration #
Date Paid
Address
Make
Amount Paid
Suburb
Type
Expiry Date
Driver Licence #
Engine #
Renewal Period
Driver
Vehicle
Renewal
Grouping Data Elements
page 83
Exercise 7.5
IT Key Ideas, Dynamic Database Systems, 2002
Chapter 7
********************************