data is the vital ingredient or raw material thatis processed in an information system. Structure of data can be examined from atechnical or logical viewpoint. determining the structure of data involvesidentifying how the individual items of data mustbe arranged.
Records data which is used by business and governmenttypically has the structure of a table. consider the problem of storing the following dataabout each student in your class: i. Name ii. age iii. birth date iv. address v. phone number
Table of dataIdentification Name Age Address Date of birth PhoneNumber NumberA10-12586 Roxane 14 10 Black St 07/08/97 661-78-22 La’O Caulfield 3162
In the example given you could organize the data in asorted order and distinguish each record by using ‘name’field.Each field has two important attributes which must becarefully chosen. 1. each field must be given a set width 2. the type of each field must be determined
Fields Type Width JustificationName C (Characters) 20 Worse case lenghtAddress C 30 Fit all dataDate of birth N (Numeric) 6 Can store 20.10.61Phone C 12 Phone numbers as characters
Relational DataStructures Many organizational problems can be easilysolved by storing data in more than one table orflat file.
Context DiagramPatrons Management System Book file Patron file Books Loan file
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-customersField Name Data type Width Validation ruleCustomer ID Number > 0 and < 20 000Customer name Character 30 Not blankAddress Character 30Suburb Character 20 Not blankPostcode Number >1000 and <10 000Phone number character 15
Data structure-booksField name Data type Width Validation RuleBook ID Number >1 and <10 000Title Character 60 Not blankRental Currency >0 and <20Rental period Number >0 and <50Date loaned DateCustomer ID Number >0 and <10 000
one patron can borrow many books; this is called oneto many relationship.However, a single video can be relate to only onecustomer; this is referred to as a one to onerelationship.
Relationships BooksCustomer Psychology Roxane English Algebra One to many relationship Book Customer Psychology One to one relationship
Design strategy for WWW documentsWhen designing the basic data structure for a World WideWeb document you should: outline the overall block structure outline each sub-documentary structure outline each sub-secondary structure.
Data structure and design of a multimedia presentation HTML and Internet-enabled documents are examples of multimediadocuments.Multimedia documents have the capacity to present information in avariety of formats: text, hypertext, sound, graphics and video.
Formats of Multimedia Presentation can be:Simple Multimedia Presentation In the past, such presentation would typically havebeen done with slides or an overhead projector. data structure of a standard presentation takes theformat of a linear sequence of slides. the most common software used for this ispowerpoint.
Complex Multimedia presentation:You will probably have seen many examples of WorldWide Web documents. many of these contain the characteristics of a simple,linear multimedia design.
Important data structure design consideration1. 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).
2. Testing and Validating Data Validation refers to the checking of data to ensure thatit is reasonable. Testing of a solution refers to the process of verifyingthat a solution produces the correct results after datahas been processed.
Validation: Input Name VALIDATEDate of Birth • Date of birth Age • Age Sex • Sex Write data to file on disk OK Record