CS/INFO%20330:%20Applied%20Database%20Systems

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CS/INFO 330Applied Database Systems

• November 18 2005
• Project Tips
• Lecturer Dan Sheldon

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Announcements

• Project Demos
• Monday, 230-430
• Tuesday, 200-400
• 328A Upson
• Sign up with Stacy Shirk, 4105 Upson

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Today

• Tips/tricks for projects
• Review Course Scheduler solutions
• Questions?

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Input Validation

• Check all user input for validity
• Print nice error messages
• DONT pass on invalid inputs, they result in
  mysterious downstream errors, and a confusing
  user experience.
• OK to do manual validation
• Check out Validator controls in ASP.NET

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Form Submission and Enter

• SubmitOnEnter.aspx get proper behavior for form
  submission when the user hits Enter instead of
  clicking the submit button
• The form submits when the user types Enter
• Usually, the click event for the first button
  fires
• In IE, click event only fires when there are
  multiple text boxes !?!?!
• Hack add an invisible textbox so IE behaves like
  Thunderbird

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SQL Tips

• Use IDENTITY column to automatically generate
  IDs for you.
• Prefer VARCHAR to CHAR!
• Use LIKE operator to find partial text matches,
  e.g., for search functionality.

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Events.aspx

• Pitfall clobber user input in Page_Load event
• Solution if (!this.IsPostBack)
• Understanding events through Tracing
• Tracetrue in Page directive
• Trace.Write()

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Course Scheduler

• Review HW solutions
• Pitfalls
• Clobbering user input in Page_Load
• Masking events in Page_Load with unnecessary
  DataBind()
• Infinite recursion with DataBind()/OnItemDataBound