need urgent help with relational algebra

• dt236

  Newbie

  Points: 1

  More actions

  November 11, 2003 at 12:34 pm

  #83551

  I was wondering if someone can help me..

  I need to find 3 differnt ways of writing the following SQL in relational algebra:

  SELECT sname

  From Student, Course, Attendance

  WHERE Student.Student# = Attendance.Student# and Course.Course# = Attendance.Course# and Course.cname = "advance database" and Student.degreetype = "professional Pathway"

  The query is : find student names that are taking professional pathway degree and are attending the advance database course.

  Student (Student#, sname, address, dob,degreetype)

  Course(Course#, cname, syllabus, day, time)

  Attendance(Student#, Course#, year)

• November 14, 2003 at 8:00 am

  This was removed by the editor as SPAM

• ThomasH

  SSCertifiable

  Points: 7437

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  November 18, 2003 at 1:49 pm

  #482502

  SELECT sname

  From Student

  Join Attendance

  On Student.Student# = Attendance.Student#

  Join Course

  On Course.Course# = Attendance.Course#

  Where Course.cname = "advance database"

  And Student.degreetype = "professional Pathway"

  SELECT sname

  From Student

  Where Student.degreetype = "professional Pathway"

  and Student.Student# In (

  Select Attendance.Student#

  From Attendance

  Join Course

  On Course.Course# = Attendance.Course#

  Where Course.cname = "advance database")

  
  
  Once you understand the BITs, all the pieces come together