Lab 09: Advanced SQL

Transcription

1 CIS395 - BMCC - Fall /14/2018 Lab 09: Advanced SQL 1- Copy and paste the following code into your SQL Editor, then execute it. This code will create the Students table. CREATE TABLE Students ( studentno VARCHAR(4), fname VARCHAR(20), lname VARCHAR(20), department VARCHAR(50), score NUMBER, PRIMARY KEY (studentno) ); 2- Run the following statements to insert sample data into the Students table. INSERT INTO Students VALUES('S288','Lucy','Treston','Mathematics',78); INSERT INTO Students VALUES('S293','Raul','Upthegrove','Mathematics',86); INSERT INTO Students VALUES('S305','Ligia','Reiber','Biology',58); INSERT INTO Students VALUES('S314','Kattie','Vonasek','Computer Science',82); INSERT INTO Students VALUES('S326','Adelina','Nabours','Physics',81); INSERT INTO Students VALUES('S337','Dulce','Labreche','Computer Science',65); INSERT INTO Students VALUES('S349','Samira','Heintzman','Mathematics',77); INSERT INTO Students VALUES('S407','Arthur','Farrow','Physics',92); INSERT INTO Students VALUES('S255','Carey','Dopico','Biology',64); INSERT INTO Students VALUES('S283','Noah','Kalafatis','Computer Science',82); INSERT INTO Students VALUES('S361','Kasandra','Semidey','Physics',93); INSERT INTO Students VALUES('S404','Teddy','Pedrozo','Computer Science',74); 3- Execute the following PL/SQL block that incorporates variables declared with explicit data types. v_fname VARCHAR(20); v_lname VARCHAR(20); v_fname := 'Lucy'; v_lname := 'Treston';

2 4- Execute the following PL/SQL block that incorporates variables declared using same types as columns from a specified table. v_fname Students.fName%TYPE; v_lname Students.lName%TYPE; v_fname := 'Arthur'; v_lname := 'Farrow'; 5- Execute the following PL/SQL block that declares and initializes variables at the declaration part. v_fname VARCHAR(20) := 'Kasandra'; v_lname VARCHAR(20) := 'Semidey'; 6- Execute the following PL/SQL block that incorporates variables assigned using the result of an SQL statement. v_fname VARCHAR(20); v_lname VARCHAR(20); SELECT fname,lname INTO v_fname,v_lname FROM Students WHERE studentno = 'S404'; 7- Execute the following PL/SQL block that incorporates a variable assigned using the result of an SQL statement with an aggregate function. v_total NUMBER; SELECT COUNT(*) INTO v_total FROM Students WHERE department = 'Physics'; DBMS_OUTPUT.PUT_LINE('Number of physics students is: ' v_total);

3 8- Execute the following PL/SQL block that incorporates a variable with multiple values. v_cookies NUMBER := 2; v_calories_per_cookie NUMBER := 300; DBMS_OUTPUT.PUT_LINE('I ate ' v_cookies ' cookies with ' v_cookies * v_calories_per_cookie ' calories.'); v_cookies := 3; DBMS_OUTPUT.PUT_LINE('I really ate ' v_cookies ' cookies with ' v_cookies * v_calories_per_cookie ' calories.'); v_cookies := v_cookies + 5; DBMS_OUTPUT.PUT_LINE('The truth is, I actually ate ' v_cookies ' cookies with ' v_cookies * v_calories_per_cookie ' calories.'); 9- Execute the following PL/SQL block that inserts a new record into the Students table. v_studentno Students.studentNo%TYPE; v_fname Students.fName%TYPE; v_lname Students.lName%TYPE; v_dpt Students.department%TYPE; vscore Students.score%TYPE; v_studentno := 'S236'; v_fname := 'Eden'; v_lname := 'Jayson'; v_dpt := 'Biology'; vscore := 86; INSERT INTO Students VALUES(v_studentNo,v_fName,v_lName,v_dpt,vscore); DBMS_OUTPUT.PUT_LINE('The Student ' v_studentno ' is added.'); 10- Check the content of the Students table and make sure the record from the previous task was added. SELECT * FROM Students;

4 Consider the example where two numeric values are stored in the variables v_num1 and v_num2. The following PL/SQL block arranges their values so that the smaller value is always stored in v_num1 and the larger value is always stored in v_num2. v_num1 NUMBER := 5; v_num2 NUMBER := 3; v_temp NUMBER; IF v_num1 > v_num2 THEN v_temp := v_num1; v_num1 := v_num2; v_num2 := v_temp; END IF; DBMS_OUTPUT.PUT_LINE('v_num1 = ' v_num1); DBMS_OUTPUT.PUT_LINE('v_num2 = ' v_num2); 11- Test the above code using different values of v_num1 and v_num Execute the following PL/SQL block that uses the IF-THEN-ELSE statement to choose between two mutually exclusive actions. v_num NUMBER := -25; IF v_num < 0 THEN DBMS_OUTPUT.PUT_LINE(v_num ' is a negative number.'); ELSE DBMS_OUTPUT.PUT_LINE(v_num ' is a positive number.'); END IF; DBMS_OUTPUT.PUT_LINE('Done.'); 13- Test the above code using different positive and negative values of v_num. 14- Execute the following PL/SQL block that uses the CASE statement to determine which group of actions to take based on the value of the operand v_dpt.

5 v_studentno VARCHAR(4) := 'S288'; v_dpt VARCHAR(50); SELECT department INTO v_dpt FROM Students WHERE studentno = v_studentno; CASE v_dpt WHEN 'Mathematics' THEN DBMS_OUTPUT.PUT_LINE('The student ' v_studentno ' is a mathematician.'); WHEN 'Biology' THEN DBMS_OUTPUT.PUT_LINE('The student ' v_studentno ' is a biologist.'); WHEN 'Physics' THEN DBMS_OUTPUT.PUT_LINE('The student ' v_studentno ' is a physician.'); ELSE DBMS_OUTPUT.PUT_LINE('The student ' v_studentno ' is a computer scientist.'); END CASE; DBMS_OUTPUT.PUT_LINE ('Student has been identified!'); 15- Test the above code using the following student numbers: S305, S326, and S Execute the following PL/SQL block that uses the CASE statement to provide the same output as Task14 but without checking the value of an operand. This statement checks search conditions. v_studentno VARCHAR(4) := 'S288'; v_dpt VARCHAR(50); SELECT department INTO v_dpt FROM Students WHERE studentno = v_studentno; CASE WHEN v_dpt = 'Mathematics' THEN DBMS_OUTPUT.PUT_LINE( 'The student ' v_studentno ' is a mathematician.'); WHEN v_dpt = 'Biology' THEN DBMS_OUTPUT.PUT_LINE( 'The student ' v_studentno ' is a biologist.'); WHEN v_dpt = 'Physics' THEN DBMS_OUTPUT.PUT_LINE( 'The student ' v_studentno ' is a physician.'); ELSE DBMS_OUTPUT.PUT_LINE('The student ' v_studentno ' is a computer scientist.'); END CASE; DBMS_OUTPUT.PUT_LINE ('Student has been identified!');

6 17- Similarly, type and execute a PL/SQL block that displays the following messages based on the score value of the student v_studentno. If the score is greater than or equal to 90, display: "The student v_studentno with the score v_score got A grade." If the score is greater than or equal to 80 and less than 90, display: "The student v_studentno with the score v_score got B grade." If the score is greater than or equal to 70 and less than 80, display: "The student v_studentno with the score v_score got C grade." If the score is greater than or equal to 60 and less than 70, display: "The student v_studentno with the score v_score got D grade." Otherwise, display: "The student v_studentno with the score v_score got F grade." Note: v_studentno and v_score, in the displayed messages, should be replaced by the student number and the score value, respectively. 18- Test the PL/SQL block you created in Task17 using the following student numbers: S305, S326, S337, and S Using an IF-THEN-ELSE statement, type and execute a PL/SQL block that displays the following messages based on the score value of the v_studentno. If the score is greater than or equal to 60, display: "The student v_studentno with the score v_score has passed." If the score is less than 60, display: "The student v_studentno with the score v_score has failed." Note: v_studentno and v_score, in the displayed messages, should be replaced by the student number and the score value, respectively. 20- Test the PL/SQL block you created in Task19 using the following student numbers: S305 and S255.