good day for u all

i've a radschadular that gets data from oracle DB the schadual is all credits avilable for students each credit has a group type/types under that group type the appointements avilablefor it.

what i need is

when the student checks one group type he can't leave to another credit if it hase more than group type untill checking all.

iwrote oracle procedure as follow to check this in the DB.

X VARCHAR2(20);
  A NUMBER;
  B NUMBER;
    
BEGIN

SELECT COUNT (GROUP_TYPE) INTO A
     FROM OLR.VIEW_COURSE_GROUP_TYPE
    WHERE COURSEID      = OLR.complete_group_type.COURSEID;
    
    
SELECT COUNT(A.GROUP_TYPE_CD) INTO B
     FROM OLR.STUDENT_REG_GROUP A
    WHERE A.STUDENTID     = OLR.complete_group_type.STUDENTID
      AND A.SEMESTERID    = (SELECT SEMESTERID FROM MSA.SEMESTER@MSA WHERE CURRENT_SEM = '1')
      AND A.COURSEID      = OLR.complete_group_type.COURSEID;
      
IF A<>B THEN

SELECT GROUP_TYPE INTO X
     FROM OLR.VIEW_COURSE_GROUP_TYPE
    WHERE COURSEID      = OLR.complete_group_type.COURSEID
    AND GROUP_TYPE NOT IN (SELECT A.GROUP_TYPE_CD
                             FROM OLR.STUDENT_REG_GROUP A
                            WHERE A.STUDENTID     = OLR.complete_group_type.STUDENTID
                              AND A.SEMESTERID    = (SELECT SEMESTERID FROM MSA.SEMESTER@MSA WHERE CURRENT_SEM = '1')
                              AND A.COURSEID      = OLR.complete_group_type.COURSEID);

RETURN ('YOU NOT CHOOSE GROUP TYPE '||X);


END IF;
EXCEPTION WHEN TOO_MANY_ROWS THEN
       RETURN ('PLEASE CHOOSE ALL COURSE GROUP TYPE');
END complete_group_type;

but i could't find the approbriate event to use it n how i used the rad shadular event appointement update

but i don't know how to use the upove function.