当前位置: Oracle DBA培训网-优技培训 >> 071题库 >

【071题库】最新OCP-071考试题库解析-第39题

【071题库】最新OCP-071考试题库解析-第39题

071考试是OCP考试科目的一种,由于071考题多变,我们专门收集整理了最新的考试题库,并对这些考题进行讲解,希望可以帮助广大考生。

每周五晚8点,我们有免费的OCP解析公开课,地址:https://ke.qq.com/course/326223  OCP题库交流群:1015267481,验证ocp

-------------------------------------------------------

071题库-第39题、choose two

Which two statements are true regarding views? (Choose two.)

A) A simple view in which column aliases have been used cannot be updated.

B) The OR REPLACE option is used to change the definition of an existing view without dropping and re-creating it.

C) The WITH CHECK OPTION constraint can be used in a view definition to restrict the columns displayed through the view.

D) Rows added through a view are deleted from the table automatically when the view is dropped.

E) Rows cannot be deleted through a view if the view definition contains the DISTINCT keyword.

F) A subquery used in a complex view definition cannot contain group functions or joins.

Answer:BE

(解析:

只要是简单视图,使用别名的列是可以使用 UPDATE 命令更新的。

WITH CHECK OPTION 用于限制通过视图更改基表的条件,禁止更改不包含在子查询条件里的行。)

技术沙龙MORE+

标签错误:<!-- #Label# labelId=20160707140604 moduleId=1 classId=12231768634 orderby=2 fields=url,title,u_info attribute= datatypeId=22192428132 recordCount=3 pageSize= <htmlTemplate><dt><img src="/images/index_26${index}.jpg" width="100" height="62" /><a href="$url" title="${title}">${title}</a><span>${api.left(u_info,60)}</span></dt></htmlTemplate> -->
我要参加技术沙龙