The EMP table contains these columns:EMPLOYEE_ID NUMBER（4)EMPNAME VARCHAR2 （25)SALARY NUMB

以下语句错误的是()

A. alter table emp delete column addcolumn;

B. alter table emp modify column addcolumn char(10);

C.alter table emp change addcolumn addcolumn int;

D. alter table emp add column addcolumn int;

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

A.DELETE * FROM　EMP

B.DELETE FROM　EMP

C.TRUNCATE TABLE　EMP

D.DELETE TABLE　EMP

A.DELETE * FROM　EMP

B.DELETE FROM　EMP

C.TRUNCATE TABLE　EMP

D.DELETE TABLE　EMP

A.alter table emp drop column addcolumn

B.alter table emp remove addcolumn

C.alter table emp delete addcolumn

D.alter table emp delete column addcolumn

A.DELETE FROM EMP;

B.TUNCATE TABLE EMP;

C.TUNCATE TABLE EMP REUSE STORAGE;

D.DROP TABLE EMP;

E.以上所述都不正确

对emp表增加雇员被雇佣时间come列，其数据类型为日期型，正确的语句是()。

A．ALTER TABLE emp ADD come Date

B．ADD TABLE emp come Date

C．ALTER TABLE emp come Date

D．ADD come Date TABLE emp

A.TRUNCATE TABLE EMP

B.DELETE TABLE EMP

C.DELETE FROM EMP

D.DELETE * FROM EMP

A．alter table emp remove addcolumn

B．alter table emp delete column addcolumn

C．alter table emp drop column addcolumn

D．alter table emp delete addcolumn

A.REVOKE SELECT ON TABLE Emp FROM U5 CASCADE

B.REVOKE SELECT ON TABLE Emp FROM U5 RESTRICT

C.REVOKE QUERY ON TABLE Emp FROM U5 CASCADE

D.GRANT SELECT ON TABLE Emp TO U5 WITH GRANT OPTION