单选题You just issued the following statement: ALTER TABLE SALES DROP COLUMN PROFIT. Which of the following choices identifies when the column will actually be removed from Oracle?（）A Immediately following statement execution B After the ALTER TABLE DROP UNU

题目
单选题
You just issued the following statement: ALTER TABLE SALES DROP COLUMN PROFIT. Which of the following choices identifies when the column will actually be removed from Oracle?（）
A

Immediately following statement execution 

B

After the ALTER TABLE DROP UNUSED COLUMNS command is issued 

C

After the ALTER TABLE SET UNUSED COLUMN command is issued 

D

After the ALTER TABLE MODIFY command is issued

相似考题

1.在VisualFoxPro中，如果要将学生表S(学号，姓名，性别，年龄)的“年龄”属性删除，正确的SQL语句是（ ）。A) ALTER TABLE S DROP COLUMN年龄B)DELETE年龄FROM SC)ALTER TABLE S DELETE COLUMN年龄D)ALTER TABLE S DELETE年龄

2.以下能够删除一列的是( )A.alter table emp remove addcolumnB.alter table emp drop column addcolumnC.alter table emp delete column addcolumnD.alter table emp delete addcolumn

3.下列说法正确的是()A.alter table user drop column sex;B.alter table user add sex varchar(20);C.alter table user drop sex;D.alter table user modify id int primary key;

4.在Visual FoxPro中，如果要将学生表S(学号,姓名,性别,年龄)中“年龄”属性删除，正确的SQL命令是______。A．ALTER TABLE S DROP COLUMN 年龄B．DELETE 年龄 FROM SC．ALTER TABLE S DELETE COLUMN 年龄D．ALTER TABLE S DELETE 年龄

更多“单选题You just issued the following statement: ALTER TABLE SALES DROP COLUMN PROFIT. Which of the following choices identifies when the column will actually be removed from Oracle?（）A Immediately following statement execution B After the ALTER TABLE DROP UNU”相关问题

  • 第1题：

    You plan to use Flashback Drop feature to recover a dropped table SALES_EMP. No other table with the same name exists in the schema.You query RECYCLEBIN and find multiple entries for the SALES_EMP table as follows, You then issue the following statement to recover the table:SQL> FLASHBACK TABLE sales_emp TO BEFORE DROP;What would be the outcome of the precedent statement?（）

    A. It retrieves the latest version of the table from the recycle bin

    B. It retrieves the oldest version of the table from the recycle bin

    C. It retrieves the version of the table for which undo information is available

    D. It returns an error because the table name is not specified as per the names in the OBJECT_NAME column


    参考答案：A

  • 第2题：

    删除student表中“平均成绩”字段的正确SQL命令是（ ）。

    A. DELETE TABLE student DELETE COLUMN平均成绩

    B. ALTER TABLE student DELETE COLUMN平均成绩

    C. ALTER TABLE student DROP COLUMN平均成绩

    D. DELETE TABLE student DROP COLUMN平均成绩


    正确答案：C
    ALTER语句用于在已有的表中添加、修改或删除字段。删除字段的格式为：alter table tablename drop column fieldname，故本题答案为C 。

  • 第3题：

    假设需要删除Customer表中的LogoutTime列,可以使用如下()方式。

    A.ALTER TABLE CUSTOMER DROP column LOGOUTTIME

    B.UPDATE TABLE DROP column LOGOUTTIME

    C.ALTER TABLE CUSTOMER DROP LOGOUTTIME

    D.UPDATE TABLE DROP LOGOUTTIME


    参考答案：A

  • 第4题：

    在 Visual FoxPro 中 ， 如果要将学生表 S( 学号 , 姓名 , 性别 , 年龄 ) 中 “ 年龄 ” 属性删除 ，正确的 SQL 命令是

    A) ALTER TABLE S DROP COLUMN 年龄

    B) DELETE 年龄 FROM S

    C) ALTER TABLE S DELETE COLUMN 年龄

    D) ALTEER TABLE S DELETE 年龄


    正确答案：A

  • 第5题：

    You just issued the following statement: ALTER TABLE SALES DROP COLUMN PROFIT. Which of the following choices identifies when the column will actually be removed from Oracle?（）

    • A、Immediately following statement execution 
    • B、After the ALTER TABLE DROP UNUSED COLUMNS command is issued 
    • C、After the ALTER TABLE SET UNUSED COLUMN command is issued 
    • D、After the ALTER TABLE MODIFY command is issued

    正确答案:B

  • 第6题：

    You issued the following command：        SQL> DROP TABLE MYTABLE；        SQL> SHOW RECYCLEBIN  The following output is returned：        ORIGINAL NAME RECYCLEBIN NAME               OBJECT TYPE      DROP TIME        ------------- ------------------------------ --------------- --------------------        MYTABLE BIN$04LhcpndanfgMAAAAAANPw==$0     TABLE           2005-01-13：20：11：31  You want to drop the table， MYTABLE， from the Recycle Bin. Which two commands can you issue to accomplish the desired task？（）

    • A、 DROP TABLE MYTABLE PURGE；
    • B、 PURGE RECYCLEBIN；
    • C、 PURGE TABLE MYTABLE；
    • D、 PURGE TABLE BIN$04LhcpndanfgMAAAAAANPw==$0；

    正确答案:C,D

  • 第7题：

    You need to change the definition of an existing table. The COMMERCIALS table needs its DESCRIPTION column changed to hold varying length characters up to 2000 bytes. The column can currently hold 1000 bytes per value. The table contains 20000 rows. Which statement is valid?（）

    • A、ALTER TABLE commercials MODIFY (description CHAR2(2000));
    • B、ALTER TABLE commercials CHANGE (description CHAR2(2000));
    • C、ALTER TABLE commercials CHANGE (description VARCHAR2 (2000));
    • D、ALTER TABLE commercials MODIFY (description VARCHAR2 (2000));
    • E、You cannot increase the size of a column if the table has rows.

    正确答案:D

  • 第8题：

    Your Oracle10g database contains a table with a TIMESTAMP TO LOCAL TIME ZONE column. There are about two hundred column values for the column. You issued the following statement：   SQL> ALTER DATABASE SET TIME_ZONE =’Europe/London’；   What will be the result of issuing the above statement？（）

    • A、 The statement will be executed successfully， and a new time zone will be set for the database.
    • B、 The statement will be executed successfully， but a new time zone will not be set for the database.
    • C、 The statement will not be executed successfully because the SET TIME_ZONE clause can be used only with the ALTER SESSION statement.
    • D、 The statement will not be executed successfully because the ALTER DATABASE SET TIME_ZONE statement is used only when the database contains no table with the TIMESTAMP TO LOCAL TIME ZONE column.

    正确答案:D

  • 第9题：

    Consider the following statement on a RANGE partitioned table: ALTER TABLE orders DROP PARTITION p1, p3; What is the outcome of executing the above statement?（）

    • A、A syntax error will result as you cannot specify more than one partition in the same statement
    • B、All data in p1 and p3 partitions are removed and the table definition is changed
    • C、All data in p1 and p3 partitions are removed, but the table definition remains unchanged
    • D、Only the first partition (p1) will be dropped as only one can be dropped at any time

    正确答案:B

  • 第10题：

    单选题
    Examine the following commands executed in your database： SQL> ALTER SESSION RECYCLEBIN=ON； Session altered  SQL > CREATE TABLE emp TABLESPACE tbsfd AS SELECT * FROM hr.employees；  Table created.  Further， you executed the following command to drop the table：  SQL> DROP TABLE emp；Table dropped.  What happens in this scenario？（）
    A

    The table is moved to the SYSAUX tablespace.

    B

    The table is moved to the SYSTEM tablespace.

    C

    The table is removed from the database permanently.

    D

    The table is renamed and remains in the TBSFD tablespace.


    正确答案： D
    解析： 暂无解析

  • 第11题：

    多选题
    You issued the following command：        SQL> DROP TABLE MYTABLE；        SQL> SHOW RECYCLEBIN  The following output is returned：        ORIGINAL NAME RECYCLEBIN NAME               OBJECT TYPE      DROP TIME        ------------- ------------------------------ --------------- --------------------        MYTABLE BIN$04LhcpndanfgMAAAAAANPw==$0     TABLE           2005-01-13：20：11：31  You want to drop the table， MYTABLE， from the Recycle Bin. Which two commands can you issue to accomplish the desired task？（）
    A

    DROP TABLE MYTABLE PURGE；

    B

    PURGE RECYCLEBIN；

    C

    PURGE TABLE MYTABLE；

    D

    PURGE TABLE BIN$04LhcpndanfgMAAAAAANPw==$0；


    正确答案： A,B
    解析： 暂无解析

  • 第12题：

    单选题
    Consider the following statement on a RANGE partitioned table: ALTER TABLE orders DROP PARTITION p1, p3; What is the outcome of executing the above statement?（）
    A

    A syntax error will result as you cannot specify more than one partition in the same statement

    B

    All data in p1 and p3 partitions are removed and the table definition is changed

    C

    All data in p1 and p3 partitions are removed, but the table definition remains unchanged

    D

    Only the first partition (p1) will be dropped as only one can be dropped at any time


    正确答案： D
    解析： 暂无解析

  • 第13题：

    Consider the following statement on a RANGE partitioned table: ALTER TABLE orders DROP PARTITION p1, p3;What is the outcome of executing the above statement?()

    A.A syntax error will result as you cannot specify more than one partition in the same statement

    B.All data in p1 and p3 partitions are removed and the table definition is changed

    C.All data in p1 and p3 partitions are removed, but the table definition remains unchanged

    D.Only the first partition (p1) will be dropped as only one can be dropped at any time


    参考答案：B

  • 第14题：

    删除student表的“平均成绩”字段的正确SQL命令是

    A．DELETE TABLE student DELETE COLUMN平均成绩

    B．ALTER TABLE student DELETE C0LUMN平均成绩

    C．ALTER TABLE student DROP COLUMN平均成绩

    D．DELETE TABLE student DROP COLUMN平均成绩


    正确答案：C
    解析： 本题考查的知识点为表结构的修改操作，命令格式为ALTER TABLE  表名[DROP[C0LUMN]字段名]。

  • 第15题：

    利用SQL命令删除“学生”表中的“年龄”字段，正确的命令格式是（ ）。

    A)ALTER TABLE 学生 DELETE COLUMN 年龄

    B)ALTER TABLE 学生 DROP COLUMN 年龄

    C)ALTER TABLE 学生 CANCEL COLUMN 年龄

    D)ALTER TABLE 学生 CUT COLUMN 年龄


    正确答案：B
    从表中删除指定字段的SQL命令是：
    ALTER TABLE表名DROP[COLUMN]字段名，其中，COLUMN可以省略。

  • 第16题：

    设有表M，将其中的Type列的数据类型改为NCHAR（4）。下列能实现该功能的语句是（）。

    • A、ALTER  TABLE  M  ADD  COLUMN  Type  NCHAR（4）
    • B、ALTER  TABLE  M  ALTER  COLUMN  Type  NCHAR（4）
    • C、ALTER  TABLE  M  DROP  COLUMN  Type  NCHAR（4）
    • D、ALTER  TABLE  M  ALTER  Type  NCHAR（4）

    正确答案:B

  • 第17题：

    Which two operations can be flashed back using the Flashback technology？（）

    • A、DROP USER SMITH；
    • B、DROP TABLE EMPLOYEES；
    • C、DROP TABLESPACE USERS；
    • D、ALTER TABLE SALES_REP DROP PARTITION P1；
    • E、ALTER TABLE EMPLOYEES DROP COLUMN DESIG_ID；

    正确答案:A,B

  • 第18题：

    Examine the following commands executed in your database： SQL> ALTER SESSION RECYCLEBIN=ON； Session altered  SQL> CREATE TABLE emp TABLESPACE tbsfd AS SELECT * FROM hr.employees；  Table created.  Further， you executed the following command to drop the table：  SQL> DROP TABLE emp； Table dropped.  What happens in this scenario？ （）

    • A、The table is moved to the SYSAUX tablespace.
    • B、The table is moved to the SYSTEM tablespace.
    • C、The table is removed from the database permanently.
    • D、The table is renamed and remains in the TBSFD tablespace.

    正确答案:D

  • 第19题：

    Your database is running in the ARCHIVELOG mode. You have configured RMAN for backup and recovery operations. You execute the following command from the RMAN prompt：   RMAN> CONFIGURE CONTROLFILE AUTOBACKUP ON；   After executing this command， in which of the following cases will RMAN make an auto-backup of the control file？ （）

    • A、 when you change the name of a datafile
    • B、 when you drop a table from the database
    • C、 when you take an export of the database
    • D、 when you back up the database using OS utilities
    • E、 when you issue an ALTER SYSTEM SWITCH LOGFILE statement
    • F、 when you issue a BACKUP command from inside the RMAN run block

    正确答案:A,E,F

  • 第20题：

    You are trying to alter the initial segment size given to a table in a dictionary-managed tablespace. Which of the following keywords would be used as part of this process?（）

    • A、DROP TABLE 
    • B、ALTER TABLE 
    • C、RESIZE 
    • D、COALESCE

    正确答案:A

  • 第21题：

    假设需要删除Customer表中的LogoutTime列，可以使用如下（）方式。

    • A、ALTER TABLE CUSTOMER DROP column LOGOUTTIME
    • B、UPDATE TABLE DROP column LOGOUTTIME
    • C、ALTER TABLE CUSTOMER DROP LOGOUTTIME
    • D、UPDATE TABLE DROP LOGOUTTIME

    正确答案:A

  • 第22题：

    单选题
    Your Oracle10g database contains a table with a TIMESTAMP TO LOCAL TIME ZONE column. There are about two hundred column values for the column. You issued the following statement：   SQL> ALTER DATABASE SET TIME_ZONE =’Europe/London’；   What will be the result of issuing the above statement？（）
    A

     The statement will be executed successfully， and a new time zone will be set for the database.

    B

     The statement will be executed successfully， but a new time zone will not be set for the database.

    C

     The statement will not be executed successfully because the SET TIME_ZONE clause can be used only with the ALTER SESSION statement.

    D

     The statement will not be executed successfully because the ALTER DATABASE SET TIME_ZONE statement is used only when the database contains no table with the TIMESTAMP TO LOCAL TIME ZONE column.


    正确答案： C
    解析： 暂无解析

  • 第23题：

    单选题
    You are managing an ASM instance. You previously issued the following statements：   ALTER DISKGROUP dg1 DROP DISK disk2；  ALTER DISKGROUP dg1 DROP DISK disk3；  ALTER DISKGROUP dg1 DROP DISK disk5；   You want to cancel the disk drops that are pending for the DG1 disk group.  Which statement should you issue？（）
    A

     ALTER DISKGROUP dg1 UNDROP disk2，disk3，disk5

    B

     ALTER DISKGROUP dg1 UNDROP

    C

     ALTER DISKGROUP dg1 UNDROP DISKS

    D

     You cannot cancel the pending disk drops


    正确答案： B
    解析： 暂无解析

  • 第24题：

    单选题
    You just issued the following statement: ALTER TABLE SALES DROP COLUMN PROFIT. Which of the following choices identifies when the column will actually be removed from Oracle?（）
    A

    Immediately following statement execution 

    B

    After the ALTER TABLE DROP UNUSED COLUMNS command is issued 

    C

    After the ALTER TABLE SET UNUSED COLUMN command is issued 

    D

    After the ALTER TABLE MODIFY command is issued


    正确答案： A
    解析： 暂无解析

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