Which of the following is illegal?(a) SELECT SYSDATE – SYSDATE FROM DUAL;(b) SELECT SYSDATE – (SYSDATE – 2) FROM DUAL;(c) SELECT SYSDATE – (SYSDATE + 2) FROM DUAL;(d) None of the Mentioned
Right answer is (d) None of the MentionedThe best explanation: SELECT SYSDATE – SYSDATE FROM DUAL; outputs 0 SELECT SYSDATE – (SYSDATE – 2) FROM DUAL; outputs 2SELECT SYSDATE – (SYSDATE + 2) FROM DUAL; outputs -2.