167.Evaluate the following DELETE statement:
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167.Evaluate the following DELETE statement:
DELETE FROM sales;
There are no other uncommitted transactions on the SALES table.
Which statement is true about the DELETE statement?
A.It would not remove the rows if the table has a primary key.
B.It removes all the rows as well as the structure of the table.
C.It removes all the rows in the table and deleted rows can be rolled back.
D.It removes all the rows in the table and deleted rows cannot be rolled back.
答案：C
解析：
A:错误，删除与主键没有关系
B:错误，只是会移除行，并不会将结构也移除，这里说的应该是drop
C:正确，删除，如果没有提交事务的话，可以通过rollback回来
D:错误
DELETE FROM sales;
There are no other uncommitted transactions on the SALES table.
Which statement is true about the DELETE statement?
A.It would not remove the rows if the table has a primary key.
B.It removes all the rows as well as the structure of the table.
C.It removes all the rows in the table and deleted rows can be rolled back.
D.It removes all the rows in the table and deleted rows cannot be rolled back.
答案：C
解析：
A:错误，删除与主键没有关系
B:错误，只是会移除行，并不会将结构也移除，这里说的应该是drop
C:正确，删除，如果没有提交事务的话，可以通过rollback回来
D:错误
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