SQL复制表中的数据

我想复制表中的一些数据，只更改一列。如下所示：

Before:

C1 C2 C3 ....  // C1 C2 C3 are columns, C3 have same value

a1 b1 c
a2 b2 c
a3 b3 c


After:  

C1 C2 C3 ....  // for the copy, all columns are same except C3, all c and f are same value

a1 b1 c
a2 b2 c
a3 b3 c
...
a1 b1 f
a2 b2 f
a3 b3 f

在sql中有什么快速的方法可以做到这一点吗？谢谢

insert into your_table (C1, C2, C3)
select C1, C2, 'f'
from your_table