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Data Elements and Tables
IT Key Ideas, Dynamic Database Systems, 2002
Chapter 7
DatabasesDatabasesTable
IT Key Ideas, Dynamic Database Systems, 2002
Record
Field
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.
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).
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.
page 75
Table
IT Key Ideas, Dynamic Database Systems, 2002
of members
Surname Given Name Address Suburb Phone TitleBurrell Patrick 7 Barker Rd Lurnea 82762798 MrBettridge Shantala 39 Heath Rd Ermington 82124396 MrsCollins Joanna 16 Penworth Lane Elanora 82938757 MrsHarding Barry 35 Princeton Tce Ermington 82947412 MrsLucas Karina 30 Holldsworth St Elanora 83844217 MrsQuintrell Holly 39 Bellington St Lurnea 82637726 MrsRobertson May 8 Grote Rd Lurnea 82683139 MrsRogers Romany 26 Young Rd Ermington 82689936 MrsWashington Leandra 7 Sherriffs Rd Elanora 82705928 MrsZengerer Sibyl 18 Junkett St Elanora 82700958 Mrs
Record
IT Key Ideas, Dynamic Database Systems, 2002
a member
LK Lucas Karina 30 Holldsworth St Elanora 83844217 Mrs
Data
IT Key Ideas, Dynamic Database Systems, 2002
a word, character
Harding Barry 35 Princeton TceLucas Karina 30 Holldsworth Quintrell Holly 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
IT Key Ideas, Dynamic Database Systems, 2002
• 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
page 75
Calculated Data Elements
IT Key Ideas, Dynamic Database Systems, 2002
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
Data Elements page 76
suggest at least six elements of data that would be stored
IT Key Ideas, Dynamic Database Systems, 2002
Data Elements
Exercise 7.1page 77
IT Key Ideas, Dynamic Database Systems, 2002
Stored or Calculated Fields
IT Key Ideas, Dynamic Database Systems, 2002
Data Element Stored or Calculated?Lesson Date
Lesson Time
Instructor
Swimmer
Number of swimmers
Date of Birth
Group
Number of lessons
Fees paid
stored
stored
stored
calculated
stored
calculated
calculated
stored
stored
Data Elements & Tables page 79
suggest at least six elements of data that would be stored in a Stores table
IT Key Ideas, Dynamic Database Systems, 2002
Store Number
Shop Number
Address
Suburb
Phone Number
Fax Number
Manager
Data Elements
Exercise 7.3page 80
IT Key Ideas, Dynamic Database Systems, 2002
Data Elements
Exercise 7.4page 81
IT Key Ideas, Dynamic Database Systems, 2002
Grouping DataElements
page 82
suggest at least ten fields and group them
IT Key Ideas, Dynamic Database Systems, 2002
Surname Registration # Date Paid
Address Make Amount Paid
Suburb Type Expiry Date
Driver Licence # Engine # Renewal Period
Driver Vehicle Renewal
Registration
Grouping Data Elements
Exercise 7.5page 83
IT Key Ideas, Dynamic Database Systems, 2002
Chapter 7
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