Spring CS Homework 2 p. 1. CS Homework 2. To practice with PL/SQL stored procedures and functions, and possibly exception handling.

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1 Spring CS Homework 2 p. 1 Deadline Due by 11:59 pm on Sunday, February 4, Purpose CS Homework 2 To practice with PL/SQL stored procedures and functions, and possibly exception handling. How to submit Each time you wish to submit, submit your homework files using ~st10/328submit on nrsprojects, with a homework number of 2. Setup for Homework Use ssh to connect to nrs-projects.humboldt.edu, and create, protect, and go to a directory named 328hw2 on nrs-projects: mkdir 328hw2 chmod hw2 cd 328hw2 Put all of your files for this homework in this directory. (And it is from this directory that you should type ~st10/328submit to submit your files each time you want to submit your work done so far.) Problem 1 Posted on the public course web site in the "References" section are the "CS 328 SQL and PL/SQL Coding Standards so far". The purpose of this problem is to give you an immediate reason to look over these. 1 part a Consider the following code -- it does NOT meet these standards, although it does compile & execute. Rewrite it in a file named hw2-bool-tool.sql such that it: includes your name and last-modified date in comment(s) meets the posted class SQL and PL/SQL coding standards (JUST improving its style, NOT changing its approach or algorithm). create or replace function bool_to_string (bool_val boolean) return varchar2 as begin if bool_val then return 'TRUE'; else return 'FALSE'; end if; end; / show errors

2 Spring CS Homework 2 p. 2 1 part b ADD to your hw2-bool-tool.sql the following, AFTER the definition of function bool_to_string: spool prob1-out.txt put a prompt command including your name put prompt command(s) saying what the call bool_to_string(true) SHOULD return then, put the SQL*Plus statements needed to call bool_to_string for the argument TRUE and show the result put prompt command(s) saying what the call bool_to_string(false) SHOULD return then, put the SQL*Plus statements needed to call bool_to_string for the argument FALSE and show the result rollback; spool off If you are not sure how to call a PL/SQL stored function using SQL*Plus commands, see the empl_count_funct.sql example posted with the Week 2 - Lecture 1 in-class examples. Submit your resulting files hw2-bool-tool.sql and prob1-out.txt. Setup for Problems 2 through 4 Now create a file 328hw2.sql. Start this file with the following: comments containing at least your name, CS Homework 2 - Problems 2-4, 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 followed by a prompt command including your name Be sure to spool off at the end of this script (after your statements for the remaining problems). Problem 2 The purpose of this problem is to give you practice writing a PL/SQL procedure including parameters, an if statement, and a loop. Recall that we discussed many lovely and useful string-related Oracle SQL functions in CS 325, including upper, that expected a column with a string domain and returned an all-uppercase version of the string in that column for each row projected. Happily, these functions can be used in PL/SQL outside of select statements, also, with string or string-variable arguments. For example, if the following were included in a PL/SQL procedure: dbms_output.put_line(lpad('moo', 12, '.'));

3 Spring CS Homework 2 p. 3...and set serveroutput on has been done, the following would be displayed to the screen:...moo In 328hw2.sql, write a SQL*Plus prompt command that says problem 2. (You may add additional prompt commands around this to make it more visible, if you would like -- assume that is the case for the remaining homework problems as well.) Design and write a PL/SQL stored procedure silly_shout that expects two parameters, a desired message and how many times it is to be "shouted" to the screen. If the number of times to shout given is less than 0, the procedure should print a message to the screen saying that it cannot show the desired message that many times; otherwise, it should print an all-uppercase version of the given message to the screen that many times, once per line, each time concatenating TWO exclamation point characters ('!!') to the end (get it? so it is "shouting" that message to the screen? 8-) ) Follow your procedure definition with at least one example call of silly_shout with a message and quantity of your choice. You will find a testing script for this function, silly_shout_test.sql, posted on the public course web site under "Homeworks and Handouts" along with this homework handout. You can also copy it to your 328hw2 directory with the command: cp ~st10/silly_shout_test.sql. # DON'T FORGET the space & period! In your 328hw2.sql, after your function definition and example call(s) for silly_shout, put a SQL*Plus statement to run your copy of this testing script: start silly_shout_test.sql Problem 3 The purpose of this problem is to give you practice writing a PL/SQL function that includes a parameter. In 328hw2.sql, write a SQL*Plus prompt command that says problem 3. Design and write a PL/SQL stored function title_total_price that expects one parameter, a title's ISBN, and returns the total PRICE (not cost!) of all of the current quantity-on-hand for that title. (If there is no title with that ISBN, it should return -1, so the caller can know that there is no such title.) Follow your function definition with at least one example call of title_total_price with an ISBN of your choice. You will find a testing script for this function, title_total_price_test.sql, posted on the public course web site under "Homeworks and Handouts" along with this homework handout. You can also copy it to your 328hw2 directory with the command: cp ~st10/title_total_price_test.sql. # NOTE the space and period!

4 Spring CS Homework 2 p. 4 In your 328hw2.sql, after your function definition and example call(s) for title_total_price, put a SQL*Plus statement to run your copy of this testing script: start title_total_price_test.sql Problem 4 The purpose of this problem is to give you practice writing a cursor-controlled for loop. In 328hw2.sql, write a SQL*Plus prompt command that says problem 4. Design and write a PL/SQL stored procedure titles_in_range which expects two parameters, the desired low end of a price range and the desired high end of a price range. For all titles whose title price (not cost!) are greater than or equal to the desired low end given, and less than or equal to the desired high end given, this procedure should display a '$' followed by the title price, a hyphen, the title name, a hyphen, and then its quantity on hand, in first order of title price (lowest to highest) and in secondary order of title name. It is fine if it simply outputs nothing if there are no titles with prices within that price range. For full credit, you must appropriately use a cursor-controlled for loop (as seen in example loopexs.sql in the Week 2, Lecture 2 in-class examples). Follow your procedure definition with at least one example call of titles_in_range with a low price value and a high price value of your choice. You will find a testing script for this function, titles_in_range_test.sql, posted on the public course web site under "Homeworks and Handouts" along with this homework handout. You can also copy it to your 328hw2 directory with the command: cp ~st10/titles_in_range_test.sql. # REMEMBER the space & period! In your 328hw2.sql, after your procedure definition and example call(s) for titles_in_range, put a SQL*Plus statement to run your copy of this testing script: start titles_in_range_test.sql Submit your resulting files 328w2.sql and 328hw2-out.txt. Problem 5 Consider "your" database, the one you specified on Homework 1 - Problem 5. What might be a useful stored function or stored procedure for your database? It does not have to be complex, but it has to be potentially useful, and you will be calling it from the application tier as part of at least one future homework problem. IMPORTANT: since you will be calling this from the application tier, you need to know that you cannot see dbms_output.put_line output from the application tier. So, for a stored procedure to be useful at that level, it will need to have some side-effect rather than just printing to the screen. For example, it might do one or more desired insert, update, or delete actions that are useful.

5 Spring CS Homework 2 p. 5 Create a file 328hw2-5.sql. Start this file with the following: comments containing at least your name, CS Homework 2 - Problem 5, and the last-modified date. include a SQL*Plus spool command to spool the results of running this SQL script to a file named 328hw2-5-out.txt followed by a prompt command including your name Be sure to spool off at the end of this script. Following the CS 328 style standards, design and implement a potentially-useful PL/SQL stored function or stored procedure for "your" database. Follow that definition with at least two testing calls that demonstrate that it works, in a similar style to those provided for you for Problems 2 through 4. (For a stored procedure, you will likely need to include one or more select statements showing that the desired side-effect(s) occurred.) Submit your resulting files 328hw2-5.sql and 328hw2-5-out.txt. (IMPORTANT NOTE: I should be able to run your Homework 1 - Problem 5's 325design.sql and 325populate.sql, and then your 328hw2-5.sql, successfully. IF you make any changes to your 325design.sql or 328populate.sql, then, make sure you submit them along with your 328hw2-5.sql!)