Some sample exam 1 questions:

1. Briefly define the following terms:


   Integrity Constraint

   Candidate Key

   Primary Key

   Foreign Key

   Entity, Entity set (in an ER model)

   Relationship, Relationship set (in an ER model)

   Key constraint (in an ER model)

   Participation constraint (ER)

   Weak entity (ER)

   ISA hierarchy (ER)


   Natural Join


   Relationally Complete


   Embedded SQL

   Dynamic SQL






2. A music database contains information about Songs (identified by a unique
   song id# and the title of the song), Bands (identified by a unique band name
   and the number of members in the band), and Albums (identified by a unique
   album id#, the title of the album, the number of songs on the album).  Bands
   sing Songs and produce Albums.  Songs are parts of an Album.  Draw an ER
   diagram for each of the situations below:

   - A Song may be part of more than one Album.
   - A Song must be part of at least one Album.
   - A Song appears on one and only one Album.
   - Each Album must have at least one Song.
   - A Band may sing more than one version of a Song, but each version must
     appear on a different Album.

3. For the following relations (keys are shown with _s over the field name):

  Student                  Class_Grade      Class
         ___               ___ ___          ___
  sname  sid  age  gpa     sid cid grade    cid cdept cnum
  --------------------     -------------    --------------
  Ann      1   21  3.5       1   1   A-       1  CS   1621 
  Bob      2   19  3.4       1   2   A        2  BIOL 1011
  Cal      3   20  2.6       2   1   B        3  ECE  1315
  Dee      4   22  4.0       2   3   C
                             3   1   A
                             3   2   C
                             3   3   F
                             4   2   A

  How would you design the following queries in Relational Algebra:

  - The id#s of students who are 19 or 20.
  - The student names (sname) of those students who have taken CS 1621.
  - Students (names) who have taken a biology course or ECE course.
  - Students (names) who have taken every course in Class.
  - Students (names) who have received an A.

4. Answer question 3 using Domain Relational Calculus.

5. Answer question 3 using SQL.

5a. How would design these queries in SQL:

    - What is the average GPA of students by age (e.g., what is the
      average GPA of students of age 18, 19, etc.)
    - What is the maximum GPA of each student by age where a result is
      reported only if there are at least 2 students of that age
    - For each course indicate the number of As in that course (only
      for courses where a student got an A)

6. Define the following operations in relational algebra:

      Selection, Projection, Cross Product, Intersection, Union,
      Natural Join, Division

   How would you perform operations similar to these in Domain Relational

7. A SQL query may have five different clauses, a SELECT, FROM, WHERE,
   GROUP BY and HAVING clause.  Explain how each of these clauses works
   and how they are evaluated in an SQL query.  Give an example using
   all five clauses.

8. How is a view defined in SQL?  How are queries on views resolved?  What
   are some of the difficulties introduced with views?

9. Define the terms primary key, candidate key, foreign key, and domain
   constraint.  How are these concepts introduced using SQL?  Give an
   example of a relation definition or definitions in SQL that includes
   all of these concepts.

10. What is a general integrity constraint in SQL?  How is such a constraint

11. Discuss two mechanisms that can be used to obtain information
    in a high-level programming language, such as Java or C++.  Make sure
    to discuss the advantages and disadvantages of each of the mechanisms.

12. How is XML related to HTML?  What are the advantages of XML?  What
    is a DTD and how does it relate to XML?  Give an example of each of
    these ideas.