Immediately following statement execution
After the ALTER TABLE DROP UNUSED COLUMNS command is issued
After the ALTER TABLE SET UNUSED COLUMN command is issued
After the ALTER TABLE MODIFY command is issued
第1题:
以下能够删除一列的是( )
A.alter table emp remove addcolumn
B.alter table emp drop column addcolumn
C.alter table emp delete column addcolumn
D.alter table emp delete addcolumn
第2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
第3题:
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 S
C)ALTER TABLE S DELETE COLUMN年龄
D)ALTER TABLE S DELETE年龄
第4题:
A.ALTER TABLE CUSTOMER DROP column LOGOUTTIME
B.UPDATE TABLE DROP column LOGOUTTIME
C.ALTER TABLE CUSTOMER DROP LOGOUTTIME
D.UPDATE TABLE DROP LOGOUTTIME
第5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
第6题:
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;
第7题:
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
第8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.ALTER TABLE S DELETE 年龄
第9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
第10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