• 2021-04-14
    ●在SQL中,下列涉及空值的操作,不正确的是 (23) 。 (23) A.AGE IS NULL B.AGE IS NOT NULL C.AGE=NULL D.NOT(AGE IS NULL)(23) A.AGE IS NULL B.AGE IS NOT NULL C.AGE=NULL D.NOT(AGE IS NULL)