Adding ch2 practice problems.

practiceProblems/week8/ch2/ch2_pp.md

+# problem 1
+
+Start SQL*Plus, log onto the database, and set up the PL/SQL output buffer using the SET SERVEROUTPUT ON command (Note: if the SET SERVEROUTPUT ON command is not used, the output will not be displayed on the screen).
+
+![problem1](./pics/problem1.png)
+
+## problem 2
+
+Write a PL/SQL program to display your name.
+
+```plsql
+begin
+  dbms_output.put_line('MICHAEL LUNDQUIST');
+end;
+/
+```
+
+![problem2](./pics/PROBLEM2.png)
+
+## problem 3
+
+Write a PL/SQL program that declares two variables (variable1 and variable2), sets their values to zero, and performs the following calculation: variable2=variable1+1 and displays the value of variable2.
+
+```plsql
+declare
+  variable1 NUMBER(2) := 0;
+  variable2 NUMBER(2) := 0;
+begin
+  variable2 := variable1 + 1;
+  dbms_output.put_line('the value of var2 is now ' || variable2);
+end;
+/
+```
+
+![problem3]("./pics/problem 3.png")
+
+## Problem 4
+
+Write a PL/SQL program to display the current date.
+
+```plsql
+begin
+  dbms_output.put_line('today is ' || sysdate);
+end;
+/
+```
+
+![problem4](./pics/problem4.png)
+
+## problem 5
+
+Write a PL/SQL program to declare a variable V_NUMBER, assign a value to it (any number), and display its’ value if the number is positive.
+
+```plsql
+declare
+V_NUMBER NUMBER(10) := 46290;
+begin
+  IF V_NUMBER >= 0 THEN
+  dbms_output.put_line('V_NUMBER IS ' || V_NUMBER);
+  END IF;
+end;
+/
+```
+
+![problem5](./pics/PROBLEM5.png)
+
+## problem 6
+
+Write a PL/SQL program to declare a variable V_NUMBER, assign a value to it (any number), and test if it is a positive number or a negative number. Display the result.
+
+```plsql
+declare
+  V_NUMBER NUMBER(10) := 46290;
+begin
+  IF V_NUMBER > 0 OR V_NUMBER < 0 THEN
+  dbms_output.put_line('V_NUMBER IS ' || V_NUMBER);
+  END IF;
+end;
+/
+```
+
+![problem6](./pics/PROBLEM6.png)
+
+## problem 7
+
+Write a PL/SQL program to test whether today is Friday or not. Display the result.
+
+```plsql
+BEGIN
+  IF to_char (SYSDATE, 'D') = '6' THEN
+     dbms_output.put_line('TODAY IS FRIDAY');
+  ELSE
+    dbms_output.put_line('TODAY IS NOT FRIDAY');
+  END IF;
+END;
+/
+```
+
+![problem7](./pics/PROBLEM7.png)
+
+## problem 8
+
+Write a PL/SQL program to test if your date of birth falls on Friday, Saturday, or Sunday. Display the result if it’s Friday, Saturday, or Sunday, otherwise print "It falls on a week-day".
+
+```plsql
+declare
+  lv_birthday_date DATE := '07-jul-1993';
+BEGIN
+  IF to_char (lv_birthday_date, 'D') = '6' THEN
+     dbms_output.put_line('Birthday on FRIDAY');
+  ELSE
+    dbms_output.put_line('birthday NOT on FRIDAY');
+  END IF;
+END;
+/
+```
+
+![problem8](./pics/problem8.png)
+
+## problem 9
+
+Write a PL/SQL program that declares a variable V_COUNTER, assigns 1 to it, and then adds 1 to the variable 5 times. Display the value of the variable every time it changes. Use the Basic LOOP structure.
+
+```plsql
+declare
+  lv_counter_num number(2) := 0;
+begin
+  loop
+    lv_counter_num := lv_counter_num + 1;
+    exit when lv_counter_num >= 5;
+  end loop;
+  dbms_output.put_line('result val ' || lv_counter_num);
+end;
+/
+```
+
+[problem9](./pics/problem 9.PNG)
+
+## problem 10
+
+Write a PL/SQL program that declares a variable V_COUNTER, assigns 1 to it, and then adds 1 to the variable 5 times. Display the value of the variable every time it changes. Use the WHILE … LOOP structure
+
+```plsql
+declare
+  V_COUNTER number(2) := 1;
+begin
+  WHILE V_COUNTER <= 5 LOOP
+    V_COUNTER := V_COUNTER + 1;
+    dbms_output.put_line('CUR VAL ' || V_COUNTER);
+  end loop;
+end;
+/
+```
+
+![problem10]("./pics/PROBLEM10.png")
+
+## problem 11
+
+Write a PL/SQL program that declares a variable V_COUNTER, assigns 1 to it, and then adds 1 to the variable 5 times. Display the value of the variable every time it changes. Use the FOR LOOP structure.
+
+```plsql
+begin
+  FOR V_COUNTER IN 1..6 LOOP
+    dbms_output.put_line('CUR VAL ' || V_COUNTER);
+  end loop;
+end;
+/
+```
+
+![problem11](./pics/PROBLEM11.png)
+
+## problem 12
+
+Write a PL/SQL program that declares a variable, assigns to it your birthday, and checks what day you were born on. Use the CASE expression. Display the result.
+
+```plsql
+declare
+  lv_birthday_date DATE := '07-jul-1993';
+  LV_DAY_CHAR CHAR(1) := to_char (lv_birthday_date, 'D');
+  LV_TEXTDAY_VCHAR VARCHAR(10);
+BEGIN
+  CASE LV_DAY_CHAR
+    WHEN '1' THEN LV_TEXTDAY_VCHAR := 'SUNDAY';
+    WHEN '2' THEN LV_TEXTDAY_VCHAR := 'MONDAY';
+    WHEN '3' THEN LV_TEXTDAY_VCHAR := 'TUESDAY';
+    WHEN '4' THEN LV_TEXTDAY_VCHAR := 'WEDNESDAY';
+    WHEN '5' THEN LV_TEXTDAY_VCHAR := 'THURSDAY';
+    WHEN '6' THEN LV_TEXTDAY_VCHAR := 'FRIDAY';
+    WHEN '7' THEN LV_TEXTDAY_VCHAR := 'SATURDAY';
+  END CASE;
+  dbms_output.put_line('YOU WERE BORN ON A ' || LV_TEXTDAY_VCHAR);
+END;
+```
+
+![problem12](./pics/PROBLEM12.png)
\ No newline at end of file

practiceProblems/week8/ch2/ch2_pp_answers.pks

+/*
+# problem 1
+
+Start SQL*Plus, log onto the database, and set up the PL/SQL output buffer using the SET SERVEROUTPUT ON command (Note: if the SET SERVEROUTPUT ON command is not used, the output will not be displayed on the screen).
+*/
+
+/*
+## problem 2
+
+Write a PL/SQL program to display your name.
+*/
+
+begin
+  dbms_output.put_line('MICHAEL LUNDQUIST');
+end;
+/
+
+/*
+## problem 3
+
+Write a PL/SQL program that declares two variables (variable1 and variable2), sets their values to zero, and performs the following calculation: variable2=variable1+1 and displays the value of variable2.
+*/
+
+declare
+  variable1 NUMBER(2) := 0;
+  variable2 NUMBER(2) := 0;
+begin
+  variable2 := variable1 + 1;
+  dbms_output.put_line('the value of var2 is now ' || variable2);
+end;
+/
+
+/*
+## Problem 4
+
+Write a PL/SQL program to display the current date.
+*/
+
+begin
+  dbms_output.put_line('today is ' || sysdate);
+end;
+/
+
+/*
+## problem 5
+
+Write a PL/SQL program to declare a variable V_NUMBER, assign a value to it (any number), and display its’ value if the number is positive.
+*/
+
+declare
+V_NUMBER NUMBER(10) := 46290;
+begin
+  IF V_NUMBER >= 0 THEN
+  dbms_output.put_line('V_NUMBER IS ' || V_NUMBER);
+  END IF;
+end;
+/
+
+/*
+## problem 6
+
+Write a PL/SQL program to declare a variable V_NUMBER, assign a value to it (any number), and test if it is a positive number or a negative number. Display the result.
+*/
+
+declare
+  V_NUMBER NUMBER(10) := 46290;
+begin
+  IF V_NUMBER > 0 OR V_NUMBER < 0 THEN
+  dbms_output.put_line('V_NUMBER IS ' || V_NUMBER);
+  END IF;
+end;
+/
+
+/*
+## problem 7
+
+Write a PL/SQL program to test whether today is Friday or not. Display the result.
+*/
+
+BEGIN 
+  IF to_char (SYSDATE, 'D') = '6' THEN
+     dbms_output.put_line('TODAY IS FRIDAY');
+  ELSE
+    dbms_output.put_line('TODAY IS NOT FRIDAY');
+  END IF;
+END;
+/
+
+/*
+## problem 8
+
+Write a PL/SQL program to test if your date of birth falls on Friday, Saturday, or Sunday. Display the result if it’s Friday, Saturday, or Sunday, otherwise print "It falls on a week-day".
+*/
+declare
+  lv_birthday_date DATE := '07-jul-1993';
+BEGIN 
+  IF to_char (lv_birthday_date, 'D') = '6' THEN
+     dbms_output.put_line('Birthday on FRIDAY');
+  ELSE
+    dbms_output.put_line('birthday NOT on FRIDAY');
+  END IF;
+END;
+/
+
+/*
+## problem 9
+
+Write a PL/SQL program that declares a variable V_COUNTER, assigns 1 to it, and then adds 1 to the variable 5 times. Display the value of the variable every time it changes. Use the Basic LOOP structure.
+*/
+declare
+  lv_counter_num number(2) := 0;
+begin
+  loop
+    lv_counter_num := lv_counter_num + 1;
+    exit when lv_counter_num >= 5;
+  end loop;
+  dbms_output.put_line('result val ' || lv_counter_num);
+end;
+/
+
+/*
+## problem 10
+
+Write a PL/SQL program that declares a variable V_COUNTER, assigns 1 to it, and then adds 1 to the variable 5 times. Display the value of the variable every time it changes. Use the WHILE … LOOP structure
+*/
+
+declare
+  V_COUNTER number(2) := 1;
+begin
+  WHILE V_COUNTER <= 5 LOOP
+    V_COUNTER := V_COUNTER + 1;
+    dbms_output.put_line('CUR VAL ' || V_COUNTER);
+  end loop;
+end;
+/
+
+/*
+## problem 11
+
+Write a PL/SQL program that declares a variable V_COUNTER, assigns 1 to it, and then adds 1 to the variable 5 times. Display the value of the variable every time it changes. Use the FOR LOOP structure.
+*/
+
+begin
+  FOR V_COUNTER IN 1..6 LOOP
+    dbms_output.put_line('CUR VAL ' || V_COUNTER);
+  end loop;
+end;
+/
+
+/*
+## problem 12
+
+Write a PL/SQL program that declares a variable, assigns to it your birthday, and checks what day you were born on. Use the CASE expression. Display the result.
+*/
+
+declare
+  lv_birthday_date DATE := '07-jul-1993';
+  LV_DAY_CHAR CHAR(1) := to_char (lv_birthday_date, 'D');
+  LV_TEXTDAY_VCHAR VARCHAR(10);
+BEGIN
+  CASE LV_DAY_CHAR
+    WHEN '1' THEN LV_TEXTDAY_VCHAR := 'SUNDAY';
+    WHEN '2' THEN LV_TEXTDAY_VCHAR := 'MONDAY';
+    WHEN '3' THEN LV_TEXTDAY_VCHAR := 'TUESDAY';
+    WHEN '4' THEN LV_TEXTDAY_VCHAR := 'WEDNESDAY';
+    WHEN '5' THEN LV_TEXTDAY_VCHAR := 'THURSDAY';
+    WHEN '6' THEN LV_TEXTDAY_VCHAR := 'FRIDAY';
+    WHEN '7' THEN LV_TEXTDAY_VCHAR := 'SATURDAY';
+  END CASE;
+  dbms_output.put_line('YOU WERE BORN ON A ' || LV_TEXTDAY_VCHAR);
+END;
+/
\ No newline at end of file