OCP-1Z0-新051-61题版本-35

QUESTION NO: 35

Examine the description of the EMP_DETAILS table given below:

Exhibit:


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

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

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

Answer: B,C

答案解析:

参考:21:http://blog.csdn.net/rlhua/article/details/10979587

Explanation:

LONG Character data in the database character set, up to 2GB. All the functionality of LONG(and

more) is provided by CLOB; LONGs should not be used in a modern database, and if your

Oracle 1z0-051 Exam

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database has any columns of this type they should be converted to CLOB. There can only be one

LONG column in a table.

Guidelines

A LONG column is not copied when a table is created using a subquery.

A LONG column cannot be included in a GROUP BY or an ORDER BY clause.

Only one LONG column can be used per table.

No constraints can be defined on a LONG column.

You might want to use a CLOB column rather than a LONG column.

原文地址:https://www.cnblogs.com/hzcya1995/p/13316212.html