Session8

							                                                                                                                Discussion Points
                                                                                                                  Websites that are really databases

 LBSC 690 Session #8
                                                                                                                  Deep vs. Surface Web
 SQL and Web Applications


                             Jimmy Lin
                             The iSchool
                             University of Maryland

                             Wednesday, October 22, 2008



       This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States                                                                 The iSchool
       See http://creativecommons.org/licenses/by-nc-sa/3.0/us/ for details                                                                                       University of Maryland




Databases in Web Applications                                                                                   Putting the Pieces Together

                       Browser                                      Browser
   Client
                         network                                     network
                                                                                                                       Browser           Web Server
   Server                                                                                                                                                                Database
                                                                                                                                 HTML

                     Web Server                                   Web Server                                                                                  y
                                                                                                                                                      SQL Query
                                                                                                                                 CGI

                                                                                                                                 HTML                  Results
                                                                “Middleware”




                       Database                                    Database




                                                                                            The iSchool                                                                       The iSchool
                                                                                University of Maryland                                                            University of Maryland




                                                                            field                                                                                field
                                                                                                                                                                       tables to join
            select address    table                                                                                           select dname
            from employee                                                                                              from employee, department
        employee.surname='Smith'
  where employee surname='Smith' and                                                                                  employee.depno=department.depno
                                                                                                                where employee depno=department depno
     employee.forenames='Robert';                                                                                       and surname='Smith' and
                                                                                                                          forenames='Robert';
                                                                                                                                                                         how to join

               how you want to restrict the rows                                                                           how you want to restrict the rows




                                                                                                                                                                                            1