Mega Code Archive
Use user-defined function in if statement
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SQL>
SQL> set serveroutput on
SQL>
SQL>
SQL>
SQL> CREATE TABLE session (
2 department CHAR(3),
3 course NUMBER(3),
4 description VARCHAR2(2000),
5 max_lecturer NUMBER(3),
6 current_lecturer NUMBER(3),
7 num_credits NUMBER(1),
8 room_id NUMBER(5)
9 );
Table created.
SQL>
SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ('HIS', 101, 'History 101', 30, 11, 4, 20000);
1 row created.
SQL>
SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ('HIS', 301, 'History 301', 30, 0, 4, 20004);
1 row created.
SQL>
SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ('CS', 101, 'Computer Science 101', 50, 0, 4, 20001);
1 row created.
SQL>
SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ('ECN', 203, 'Economics 203', 15, 0, 3, 20002);
1 row created.
SQL>
SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ('CS', 102, 'Computer Science 102', 35, 3, 4, 20003);
1 row created.
SQL>
SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ('MUS', 410, 'Music 410', 5, 4, 3, 20005);
1 row created.
SQL>
SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ('ECN', 101, 'Economics 101', 50, 0, 4, 20007);
1 row created.
SQL>
SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ('NUT', 307, 'Nutrition 307', 20, 2, 4, 20008);
1 row created.
SQL>
SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ('MUS', 100, 'Music 100', 100, 0, 3, NULL);
1 row created.
SQL>
SQL>
SQL> CREATE OR REPLACE FUNCTION AlmostFull (
2 p_Department session.department%TYPE,
3 p_Course session.course%TYPE)
4 RETURN BOOLEAN IS
5
6 studentCount NUMBER;
7 studentMax NUMBER;
8 v_ReturnValue BOOLEAN;
9 v_FullPercent CONSTANT NUMBER := 80;
10 BEGIN
11 SELECT current_lecturer, max_lecturer
12 INTO studentCount, studentMax
13 FROM session
14 WHERE department = p_Department
15 AND course = p_Course;
16
17 IF (studentCount / studentMax * 100) >= v_FullPercent THEN
18 v_ReturnValue := TRUE;
19 ELSE
20 v_ReturnValue := FALSE;
21 END IF;
22
23 RETURN v_ReturnValue;
24 END AlmostFull;
25 /
Function created.
SQL>
SQL>
SQL> DECLARE
2 CURSOR c_session IS
3 SELECT department, course
4 FROM session;
5 BEGIN
6 FOR v_ClassRecord IN c_session LOOP
7 IF AlmostFull(v_ClassRecord.department, v_ClassRecord.course) THEN
8 DBMS_OUTPUT.PUT_LINE(v_ClassRecord.department || ' ' || v_ClassRecord.course || ' is almost full!');
9 END IF;
10 END LOOP;
11 END;
12 /
MUS 410 is almost full!
PL/SQL procedure successfully completed.
SQL>
SQL> drop table session;
Table dropped.
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