OCP考试题库：11g-1Z0-051-v9.02-021题

OCP考试题库：11g-1Z0-051-v9.02-021题,完整题库请点击这里联系老师咨询了解

21. Examine the description of the EMP_DETAILS table given below:

name NULL TYPE

EMP_ID NOT NULL NUMBER

EMP_NAME NOT NULL VARCHAR2 (40)

EMP_IMAGE LONG

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

table? (Choose two.)

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

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

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

D. You can alter the table to include the NOT NULL constraint on the EMP_IMAGE column.

Answer: BC

试题解析：

准则

在使用子查询创建表时不复制LONG列。

不能在GROUP BY或ORDER BY子句中包括LONG列。

每个表只能使用一个LONG列。

不能对LONG列定义约束条件。

可以要求使用CLOB列，而不是LONG列。