【OCP-12c】CUUG 071题库考试原题及答案解析（20）

20.choose two


Examine the description of the EMP_DETAILS table given below:






Which two statements are true regarding SQL statements that can be executed on the EMP_DETAIL table?


A) You cannot add a new column to the table with LONG as the data type.


B) An EMP_IMAGE column can be included in the GROUP BY clause.


C) You can alter the table to include the NOT Nun., constraint on the EMP_IMAGE column.


D) An EMP_IMAGE column cannot be included in the ORDER BY clause.






Answer:AD


(解析：


答案 A：


SQL> alter table sales add emp_info long;


alter table sales add emp_info long *


第 1 行出现错误:


ORA-01754: 表只能包含一个 LONG 类型的列。


答案 D：


SQL> select * from sales


2 order by emp_image;


select * from sales


*


第 1 行出现错误:


ORA-00997: 非法使用 LONG 数据类型


）