Warning! The Web site for this class is in beta form.
Assigned: Wednesday, 27 October 2010
Due: 8 p.m., Friday, 5 November 2010
This is a take-home examination. You may use any time or times you deem
appropriate to complete the exam, provided you return it to me by the
due date.
There are four problems on this examination. They are not necessarily
of equal difficulty. Each problem may include subproblems. Four correct
or mostly-correct solutions will earn you an A. Three correct
or mostly-correct solutions will earn you a B. Two correct or
mostly-correct solutions will earn you a C. One correct or mostly-correct
solutions will earn you a D. Zero correct or mostly-correct
solutions will earn you an F. Failure to attempt the exam will earn you
a 0. Partially-correct solutions may or may not earn you a partial grade,
at the discretion of the grader.
Read the entire exam before you begin.
I expect that someone who has mastered the material and works at a
moderate rate should have little trouble completing the exam in a
reasonable amount of time. In particular, this exam is likely to take
you about eight hours, depending on how well you've learned the topics
and how fast you work. You should not work more than twelve hours on this
exam. Twelve hours of work, documented attempts on all four problems, and
a signed statement that There's more to life than computer science
will earn you at least a C on this exam.
I would also appreciate it if you would write down the amount of time
each problem takes.
This examination is open book, open notes, open mind, open computer,
open Web. However, it is closed person. That means you should not talk to
other people about the exam. Other than as restricted by that limitation,
you should feel free to use all reasonable resources available to you.
As always, you are expected to turn in your own work. If you find ideas
in a book or on the Web, be sure to cite them appropriately. If you use
code that you wrote for a previous lab or homework, cite that lab or
homework and the other members of your group. If you use code that you
found on the course Web site, be sure to cite that code. You need not
cite the code provided in the body of the examination.
Although you may use the Web for this exam, you may not post your answers
to this examination on the Web. And, in case it's not clear, you may
not ask others (in person, via email, via IM, by posting a please help
message, or in any other way) to put answers on the Web.
Because different students may be taking the exam at different times,
you are not permitted to discuss the exam with anyone until after I have
returned it. If you must say something about the exam, you are allowed
to say This is among the hardest exams I have ever taken. If you
don't start it early, you will have no chance of finishing the exam.
You may also summarize these policies. You may not tell other students
which problems you've finished. You may not tell other students how long
you've spent on the exam.
You must include both of the following statements on the cover sheet of the examination.
- I have neither received nor given inappropriate assistance on this examination.
- I am not aware of any other students who have given or received inappropriate assistance on this examination.
Please sign and date each statement. Note that the statements must be true; if you are unable to sign either statement, please talk to me at your earliest convenience. You need not reveal the particulars of the dishonesty, simply that it happened. Note also that inappropriate assistance is assistance from (or to) anyone other than Professor Rebelsky (that's me).
You must present your exam to me in two forms: both physically and
electronically. That is, you must write all of your answers using the
computer, print them out, number the pages, put your name on the top of
every page, and hand me the printed copy. You must also email me a copy
of your exam. You should create the emailed version by copying the various
parts of your exam and pasting them into an email message. In both cases,
you should put your answers in the same order as the problems. Failure
to name and number the printed pages will lead to a penalty.
Failure to turn in both versions may lead to a much worse penalty.
Failure to turn in a legible version of the exam is also likely to lead
to a penalty.
In many problems, I ask you to write code. Unless I specify otherwise
in a problem, you should write working code and include examples that
show that you've tested the code.
Unless I explicitly tell you not to document a procedure, you should
assume that you must document every procedure you write using six-P
style documentation. You need not document main or
procedures whose primary purpose is to run unit tests.
Just as you should be careful and precise when you write code and
documentation, so should you be careful and precise when you write
prose. Please check your spelling and grammar. Since I should be equally
careful, the whole class will receive one point of extra credit for each
error in spelling or grammar you identify on this exam. I will limit
that form of extra credit to five points.
I may give partial credit for partially correct answers. I am best able
to give such partial credit if you include a clear set of work that
shows how you derived your answer. You ensure the best possible grade
for yourself by clearly indicating what part of your answer is work and
what part is your final answer.
I may not be available at the time you take the exam. If you feel that
a question is badly worded or impossible to answer, note the problem
you have observed and attempt to reword the question in such a way that
it is answerable. If it's a reasonable hour (before 10 p.m. and after 8
a.m.), feel free to try to call me in the office (269-4410) or at home
(236-7445).
I will also reserve time at the start of each class before the exam is
due to discuss any general questions you have on the exam.
Topics: Extreme Programming
In Section 2 of Extreme Programming Explained, Kent Beck provides
a list of twelve key practices of Extreme Programming (XP).
Suppose you were told to adapt XP to your project for this class.
Clearly, not all of the XP practices would work as given (e.g., a
40-hour week for one class is probably not appropriate). Nonetheless,
we could adapt them (e.g., a 15-hour week for this class may be appropriate).
Identify the four most important practices to adapt or adopt for this
class's project and explain why these four practices are more important
than the rest.
Identify the least important practice to adapt or adopt for this class's
project and explain why this practice is less important than the rest.
Topics: SQL, Reliability
In our consideration of the books database, we noted that it was important
to avoid entering duplicate authors. While we could rely on practices
to ensure that there are no duplicates (e.g., locking the table and
checking for the author before adding an author) such practices are just
that, practices.
However, Bowman et al. suggest that we should be designing our databases
so that they ensure consistency. We would therefore hope that we could use
SQL to specify that duplicates are not permitted.
a. Provide SQL code to create an authors table that will not allow
duplicate author names. You must preserve the AuthorID field as primary
key, since the books table relies on it.
Another reliability issue that has cropped up in the database is that
we can delete authors, leaving the AuthorID link in the books table
dangling.
b. Provide instructions for creating the books and authors tables in
such a way that either (1) an author whose ID is used by the books table
cannot be deleted or (2) when an author's ID is deleted, all books by that
author are also deleted.
Topics: SQL, PHP
In your interface for querying the books database, you wrote fairly
repetitious code. In essence, for each possible field that you might
use, you extended the WHERE clause.
Write a PHP procedure, makeSelect(tables, desired), that
takes two parameters, an array of table names and an associative array
of whose keys are attribute names and whose values are desired values
for those attributes, and builds a select query that looks for all the
values in the combination of the tables in which the designated fields
contain the designated values.
Your procedure must ensure that when two tables have the same field name,
the query requires that those two fields be the same.
Topics: SQL, PHP, HTML/CSS
In a recent assignment, you wrote a user interface to insert data into a
group of related tables. Clearly, it would be useful to generalize that
code.
a. Write a function, generateForm(tables) that builds
a appropriate form for inserting into a set of linked tables. You should
not include the ID fields (which link the tables) in that form.
b. Write a function, insertData(tables,info), that has
two parameters, an array of table names and an associative array
of attribute/value pairs, and inserts the data appropriately
.
You should do your best to avoid duplicating values. (You may design
the policy that says when a new entry is a duplicate.)
c. Using these functions, build a new user interface (UI) for the books database.
Here you will find answers to questions of general interest. Please check here before emailing your questions!
- Can we get extra credit for finding errors in the Q&A section or the errata?
- No. I'd still appreciate hearing about the errors, but the policy only applies to the main part of the test.
- Who makes the decision as to whether or not a correction is acceptable.
- I do.
- Is that fair?
- I don't care.
Here you will find errors of spelling, grammar, and design that students have noted. Remember, each error found corresponds to a point of extra credit for everyone. We usually limit such extra credit to five points. However, if I make an astoundingly large number of errors, then I will provide more extra credit.
- Cut-paste-and-change not quite successful when switching from five problems to four. [AH, 1 point]
- Inconsistency in use of abbreviations. [AH, 1 point]
- Sam seems to spell "and" as "are". [Lots of people, 1 point]
Tuesday, 26 September 2010 [Samuel A. Rebelsky]
Wednesday, 3 November 2010 [Samuel A. Rebelsky]
Friday, 5 November 2010 [Samuel A. Rebelsky]
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