please answer both parts

Consider the following PL/SQL script: SET SERVEROUTPUT ON BEGIN INSERT INTO COURSE (course_no, description, created_by, created-date, modified_by, modified_date) VALUES (course_no_seq.nextval, 'database development', USER, SYSDATE); COMMIT DBMS_OUTPUT.PUT_LINE ("one course has been added' ); END; Assumptions: All the COURSE table fields have check constraints defined on them indicating that none can be null. 1. Explain why the script does not execute successfully. (3 marks) 2. Add a user-defined exception to the script, so that the error generated by the INSERT statement is handled. Assign the code 2290 to this exception. (5 mark orthotolboros ATC10 DCC ALTCN 10 INC