CS Homework 2. Deadline. How to submit. Purpose. Initial set of CS 328 PL/SQL and SQL coding standards

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1 CS Homework 2 p. 1 Deadline Due by 11:59 pm on Friday, February 6, How to submit CS Homework 2 Submit your files for this homework using ~st10/328submit on nrs-projects, with a homework number of 2 Instructions for using the tool ~st10/328submit If they are not already on nrs-projects, transfer your files to be submitted to a directory on nrs-projects. You can do so by using sftp (secure file transfer) and connecting to nrsprojects.humboldt.edu, and then transferring them Once all of your files to be submitted are in a directory on nrs-projects, then use ssh (or PuTTY in an Academic Computing lab) to connect to nrs-projects.humboldt.edu. use cd to change to the directory containing the files to be submitted -- for example, cd 328hw02 type the command: ~st10/328submit...and give the number of the homework being submitted (or whatever number you have been asked to do for lab-related files) when asked, and answer that, y, you do want to submit all of the files with of-interestto-328 suffixes in the current directory. (Note that I don't mind if a few extraneous files get submitted as well -- I'd rather receive too many files that too few, and typing in all of the file names for each assignment is just too error-prone...) you are expected to carefully check the list of files that the tool believes have been submitted, and make sure all of the files you hoped to submit were indeed submitted! (The most common error is to try to run ~st10/328submit while in a different directory than where your files are.) Purpose To practice with PL/SQL stored procedures and functions. Initial set of CS 328 PL/SQL and SQL coding standards Here is an opening/beginning set of CS 328 SQL and PL/SQL Style Standards -- your SQL and PL/SQL code is expected to conform to these standards: THOU SHALT precede each PL/SQL subroutine with an opening comment block that includes at least: the subroutine's name

2 CS Homework 2 p. 2 a purpose statement which explicitly describes what the subroutine expects (for a trigger, describe when it is fired), and what it does and/or returns THOU SHALT put a blank line before and after each SELECT statement, before and after each PL/SQL subroutine, and usually before each multi-line SQL statement, for better readability. And logically group SQL*Plus statements within a script as well. THOU SHALT write a SELECT statement's FROM clause on its OWN line. THOU SHALT write the beginning of a SELECT statement's WHERE clause on its OWN line. THOU SHALT indent nested selects by at least 4 spaces. When a SELECT statement has N tables/relations in its FROM clause (OR for joins written using the INNER JOIN syntax), THOU SHALT have (N-1) join conditions (unless one REALLY, TRULY wants a true Cartesian product, a rare occurrence...). THOU SHALT use mnemonic table aliases (d and e for tables dept and empl, for example, not x and y...). THOU SHALT only use GROUP BY clauses when one has a good reason (usually a computation that you wish done to those groups). THOU SHALT only use ORDER BY clauses for an outermost SELECT (not within any sub-selects), and it shall be indented to make clear that it "belongs" to the outermost SELECT....and I reserve the right to add to this list over the course of the semester. Problem 1-20 points Create a file 328hw2.sql. Start this file with the following: comments containing at least your name, CS Homework 2, and the last-modified date. include the command to set serveroutput on followed by a SQL*Plus spool command to spool the results of running this SQL script to a file named 328hw2-out.txt. Be sure to spool off at the end of this script (after your statements for the remaining problems). Then, write a SQL*Plus command that says problem 1. (You may add additional commands around this to make it more visible, if you would like.) Now, not everyone finished the Week 2 Lab Exercise -- and one student found a very interesting case to test for that I had not previously considered. SO -- a slightly-recast version of these subroutines will start out this homework. (Did your lab partner submit your Week 2 Lab Exercise files? me, and I'll be glad to e- mail you a copy of what your pair submitted.) (BE CAREFUL to note the CHANGES here as compared to the Week 2 Lab Exercise!!) Write a PL/SQL stored function get_manager that expects the name of an employee and returns the name of that employee's manager -- IF the name given is not that of an employee, it should return the string 'Not an employee'. And, if TWO or more employees have that name, it should return the string 'Name not unique'. THIS has an interesting wrinkle to beware of -- what if two or more employees with the same name

3 CS Homework 2 p. 3 happen to have the same manager? After some consideration/waffling, I decided I still want this case to return the string 'Name not unique'. And a test for this case is included below. Finally, if there is only one employee with that name, but that employee has no manager, it should return the string 'No manager' instead of NULL. Also -- still to provide a first simple experience of calling one PL/SQL subroutine within another PL/SQL subroutine -- write a PL/SQL stored procedure show_manager that expects the name of an employee and prints to the screen the result of calling get_manager in a message that includes the given employee name and the given employee's manager's name (OR whatever get_manager returned for that employee!) BUT because I want to add the very-particular case noted above, I'll give you the testing calls for these subroutines: ************************************* TESTING show_manager and get_manager ************************************* set serveroutput on -- test set-up: adding some additional employees commit; -- this employee also happens to be named Jones - but this -- Jones does have a different manager than the -- existing Jones insert into empl values ('8001', 'Jones', 'Salesman', '7698', sysdate, 1000, 0, '300'); -- this employee also happens to be named Ward - AND also -- happens to have the same manager as the other employee -- named Ward... insert into empl values ('8002', 'Ward', 'Salesman', '7698', sysdate, 1000, 0, '300'); these 2 tests pass if they both show that Raimi has manager King: ========================================================== exec show_manager('raimi') var manager_string varchar2(20) exec :manager_string := get_manager('raimi') these 2 tests pass if they both show that Ford has manager Jones:

4 CS Homework 2 p. 4 ========================================================== exec show_manager('ford') exec :manager_string := get_manager('ford') these 2 tests pass if they show that King has manager result of 'No manager' ===================================================== exec show_manager('king') exec :manager_string := get_manager('king') these 2 tests pass if they show that Willbon has manager result of 'Not an employee' ===================================================== exec show_manager('willbon') exec :manager_string := get_manager('willbon') these 2 tests pass if they show that Jones has manager result of 'Name not unique' (because 2 empls named Jones) ===================================================== exec show_manager('jones') exec :manager_string := get_manager('jones') these 2 tests pass if they show that Ward has manager result of 'Name not unique' (because 2 empls named Ward) ===================================================== exec show_manager('ward') exec :manager_string := get_manager('ward') -- and now remove the 2 employees added for testing purposes rollback; Debug and correct get_manager and show_manager as necessary until they pass the above tests and you are convinced that they are working. You may add additional testing calls if you would like.

5 CS Homework 2 p. 5 Problem 2-20 points Write a SQL*Plus command that says problem 2. (Again, you may add additional commands around this to make it more visible, if you would like -- assume that is the case for the remaining homework problems as well.) Then, design and write a PL/SQL stored procedure title_total_cost that expects one parameter, a title's ISBN, and prints to the screen a message that gives the total COST (not price!) of all of the current quantity-on-hand for that title. This message should also include the title's ISBN and its current quantity on hand. (If there is no title with that ISBN, it should print a message saying so, also including that non-existent ISBN in the error message.) After this stored procedure, include the following testing calls for this procedure: ************************ TESTING title_total_cost ************************ test passes if it shows that ISBN has 35 copies on hand with a total cost of $1137.5: ========================================================== exec title_total_cost(' ') test passes if it shows that ISBN X has 3 copies on hand with a total cost of $79.5 ===================================================== exec title_total_cost(' x') test passes if it shows that there is NO title with ISBN ===================================================== exec title_total_cost(' ') Debug and correct title_total_cost as necessary until it passes the above tests and you are convinced that it is working. You may add additional testing calls if you would like. Problem 3-20 points Write a SQL*Plus command that says problem 3. Then, design and write a PL/SQL stored procedure silly_shout, to try your hand at PL/SQL's LOOP and IF statements. silly_shout expects two parameters, an integer parameter and a VARCHAR2 parameter. If the integer is less than or equal to 0, the procedure should print a message to the screen saying that it cannot show the parameter string that many times; otherwise, it should print that parameter string to the screen that many times, once per line, each time concatenating an exclamation point character ('!') to the end (get it? so it is "shouting" that parameter to the screen? 8-) )

6 CS Homework 2 p. 6 After this stored procedure, include the following testing calls for this procedure: ************************ TESTING silly_shout ************************ test passes if it shows 3 "shouts" of howdy!: ========================================================== exec silly_shout(3, 'howdy') test passes if it shows 5 "shouts" of CS RAH RAH RAH!! ========================================================== exec silly_shout(5, 'CS RAH RAH RAH!') test passes if it complains that it can't "shout" hi 0 times: ========================================================== exec silly_shout(0, 'hi') test passes if it complains that it can't "shout" moo -1 times: ========================================================== exec silly_shout(-1, 'moo') Debug and correct silly_shout as necessary until it passes the above tests and you are convinced that it is working. You may add additional testing calls if you would like. Problem 4-20 points Write a SQL*Plus command that says problem 4. Then, design and write a PL/SQL stored function total_on_hand. total_on_hand expects one parameter, the publisher name, and returns the sum of all of the current quantity on hand amongst all of the titles from the publisher with that name. (If there is no publisher with that name, it should just return 0.) For example, the call total_on_hand('prentice Hall') returns 22, the call total_on_hand('merrill') returns 0, and the call total_on_hand('nonexistent') returns 0. After this stored function, include the following testing calls: ********************************* TESTING total_on_hand ********************************* var result_total number; test passes if it shows Prentice Hall's total quantity on hand is 22: ========================================================== exec :result_total := total_on_hand('prentice Hall')

7 CS Homework 2 p. 7 print result_total test passes if it shows Addison-Wesley's total quantity on hand is 30: ========================================================== exec :result_total := total_on_hand('addison-wesley') print result_total test passes if it shows Merrill's total quantity on hand is 0: ========================================================== exec :result_total := total_on_hand('merrill') print result_total test passes if it shows nonexistent's total quantity on hand is 0: ========================================================== exec :result_total := total_on_hand('nonexistent') print result_total Debug and correct total_on_hand as necessary until the above tests succeed and you are convinced that it is working. You may add additional testing calls if you would like. Problem 5-20 points Write a SQL*Plus command that says problem 5. Then, design and write a PL/SQL stored procedure which_titles which expects two parameters, which I'll call quant_limit and price_limit. which_titles should print the title name, quantity on hand, and price (separated by hyphens, with a '$' before the price) of each title whose qty_on_hand >= quant_limit and whose price >= price_limit. For example, SQL> exec which_titles(15, 20)...should result in: Computers and Data Processing-15-$34.95 Data Base Management-20-$37.95 Intro to Biology: A Human-35-$41.95 SPSS-75-$28.95 Management Information Sy-30-$ being printed to the screen. After this stored procedure, include the following testing calls for this procedure: *********************************

8 CS Homework 2 p. 8 TESTING which_titles ********************************* testing JUST for titles with >= 15 copies on hand AND whose price is >= $20 ( test passes if 5 titles, quantities, and prices are shown;) ( see Homework 2 handout for exact expected values): ========================================================== exec which_titles(15, 20) testing JUST for titles with >= 10 copies on hand AND whose price is >= $40 ( test passes if 3 titles, quantities, and prices are shown): ========================================================== exec which_titles(10, 40) testing JUST for titles with >= 15 copies on hand AND whose price is >= $100 ( as you can see in the previous results, there should) ( be NO such titles found): ========================================================== exec which_titles(15, 100) testing JUST for titles with >= 100 copies on hand AND whose price is >= $20 ( again, as you can see in the first test's results, there) ( should be NO such titles found): ========================================================== exec which_titles(100, 20) testing JUST for titles with >= 100 copies on hand AND whose price is >= $100 ( again, as you can see in the first test's results, there) ( should be NO such titles found): ========================================================== exec which_titles(100, 100) Debug and correct which_titles as necessary until it passes the above tests and you are convinced that it is working. You may add additional testing calls if you would like.