Java and Database Connectivity

Join

Once we have relationships, we can join tables to produce more useful data.

• Where does Jane Doe have to go, and on which days?

      select VENUE.Name, WORKSHOP.Date
        from ATTENDEE, ATTENDANCE, WORKSHOP, VENUE
       where ATTENDEE.Name = 'Jane Doe'
         and ATTENDEE.Attendee = ATTENDANCE.Attendee
         and ATTENDANCE.Workshop = WORKSHOP.Workshop
         and WORKSHOP.Venue = VENUE.Venue
    order by WORKSHOP.Date;
      
  

• Who is coming to Simon Brooke's workshops?

      select distinct ATTENDEE.Name 
        from ATTENDEE, ATTENDANCE, WORKSHOP
       where ATTENDEE.Attendee = ATTENDANCE.Attendee
         and ATTENDANCE.Workshop = WORKSHOP.Workshop
         and WORKSHOP.Tutor = 'Simon Brooke';
      
  

Full text of this presentation | Table of Contents | No Frames Author: Simon Brooke | Copyright © 2001 Simon Brooke Slide 59 of 95

give me feedback on this page // show previous feedback on this page