CREATE OR replace PACKAGE school_api
AS
  PROCEDURE remove_student (
    s_id student.student_id%TYPE,
    p_ri VARCHAR2 DEFAULT 'R');
END school_api;

/
CREATE OR replace PACKAGE BODY school_api
AS
  PROCEDURE Remove_student(s_id student.student_id%TYPE,
                           p_ri VARCHAR2 DEFAULT 'R')
  IS
  BEGIN
      dbms_output.Put_line(p_ri);

      IF p_ri = 'R' THEN
        DELETE FROM student
        WHERE  student_id = s_id;
      ELSIF p_ri = 'C' THEN
        DELETE FROM grade
        WHERE  student_id = s_id;

        DELETE FROM enrollment
        WHERE  student_id = s_id;

        DELETE FROM student
        WHERE  student_id = s_id;
      END IF;
  END remove_student;
END school_api;

/
SET serveroutput ON
DECLARE
    v_student_id NUMBER := &v_student_id;
    v_pr_i       VARCHAR2(1) := '&v_pr_i';
BEGIN
    school_api.Remove_student(v_student_id, v_pr_i);

    dbms_output.Put_line(v_student_id);
END;