题目内容:
●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)
参考答案:
(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)