（21）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? (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.

答案：（B、C）

解析：

不能按LONG类型的列进行排序，也不能进行GROUP BY, 也不能给LONG类型的列添加NOT NULL约束。

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Oracle Certificate Profession 1Z0-051-21