Creating Databases for Web Applications

1
Creating Databases for Web Applications

• Library diagrams
• Continue with diagrams for video clip archive and
  for (Flash) grid design. General and specific
  comments on interfaces.
• Homework Finish exercises. Look at Flash video
  archive program.

2
Caution

• The word 'design' may refer to
• Design (plan, structure, organization,
  definition) of the database and the application
• The look of an application
• One of my examples the design of a grid using
  pre-defined units.

3
Library design homework

• What are entities?
• What are processes?

4
Class exercises

• Application database for CD collection kept in
  various places (home, office, car)
• Tables artists/groups CDs ???
• addition keep track of CDs on loan to friends?
  This probably requires a friends table.
• Write down fields for each table
• What are relationships?
• What processes would you want?
• what maintenance functions do you want to have?
• what questions would you want to ask?

5
Class exercises

• Now, let's agree on a new application (more than
  one table)

6
Video clips DFD
A different type of data store

Select by category
Clip info (two tables)
Clip viewer
Add (edit) clips
Video clips
DB administrator
Select by tag
7
Reflection

• Some may argue with my diagram. NO one right way
  to do this.
• What I want to convey
• The viewer requests a video clip using
  information from the database.
• The db administrator is the only one changing
  information in the database
• The actual playing of the videos is a distinct
  operation of the two processes

8
Storyboard for video project housekeeping

maketable2.php
maketagtable2.php
deleteall.php
showtable2.php
showtagtable2.php
addclip2t.html
addtotableform2t.php
removeclip.html
removefromtable.php
9
Storyboard for video archive operation

getgroups.php
Choosevideo.fla Video3.as
getgroupclips.php
gettags.php
tagdisplay.fla Tags.as
gettagclips.php
10
Comments

• Tags were an after-thought.
• There were more housekeeping functions
• Both before the addition of the second table
• For trying things out inputing a single,
  specific clip record
• Names are okay, but could be better.
• More consistent

11
DFD for grid design

Design program (FLASH)
Local storage (shared object)
Designer
Web storage (database)
Company producing design
produce designs
12
What diagram says

• Designer works with one program
• Designs can be stored locally or centrally
• This was demonstration application. The company
  production part is not implemented. The diagram
  indicates the potential presence of this other
  agent.

13
Storyboard for grid design
storedesign (php)
makedesign (Flash)
fetchdesign (php)
14
Notes

• Diagram doesn't convey asynchronous nature of the
  Flash-php connection
• Diagram doesn't convey anything about the local
  storage using SharedObject
• Option block indicating browser?
• Diagram DOES convey code that I intended to write
  and did write

15
Interface Video clip archive

• html to php form data (_GET, _POST, or
  _Request
• php back to browser html!
• Flash program to php form data
• php back to the Flash program my own invention
  string with commas and

16
Interface grid design

• Flash program to php form data, including a
  string that is XML converted to string
• php back to Flash string that will be converted
  to XML

17
Interfaces

• Interfaces between your own programs are your
  choice!
• ActionScript 3.0 has facilities for handling XML
  and
• Functions such as split for breaking up strings
  into arrays

18
Homework

• Catch up for Library
• Book store
• Election ballot information
• IPOD
• Catch up regular expressions
• GET SIMPLE EXAMPLES WORKING and then make them
  your own
• Look over ActionScript coding for video archive.
  Will review some details next class.