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【OCP-12c】CUUG 071题库考试原题及答案解析(13)

时间:2019-02-18 16:05:20      阅读:134      评论:0      收藏:0      [点我收藏+]

标签:UNC   row   single   which   sel   select   dep   cannot   表达式   

13、(6-7) choose two
Which two statements are true regarding operators used with subqueries? (Choose two.)
A) =ANY and =ALL operators have the same functionality.
E) The NOT IN operator is equivalent to is NULL.
C) The <ANY operator means less than the maximum.
D) The NOT operator can be used with IN, ANY and ALL operators.
E) The IN operator cannot be used in single-row subqueries.
Answer:CD
(解析:051 曾经出现过,但是当时是单选题,答案是 D,这个语法比较少见。
其实就是把 NOT 放到整个表达式之前,下面条件执行的结果都是一样,考大家的逻辑思维能力:
WHERE NOT col IN (SELECT ...)(也可以是 WHERE col not IN (SELECT ...))
WHERE NOT col = ANY (SELECT ...)(大于、小于都可以)
WHERE NOT col = ALL (SELECT ...)(大于、小于都可以)
SQL> select deptno from emp
2 where not deptno in (select deptno from dept where deptno=10);
DEPTNO

20
30
30
....
或者:
select deptno from emp
where not deptno = all (select deptno from dept where deptno=10);

【OCP-12c】CUUG 071题库考试原题及答案解析(13)

标签:UNC   row   single   which   sel   select   dep   cannot   表达式   

原文地址:http://blog.51cto.com/13854012/2351296

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