Duplicate Column Values MySQL

Is there a way I can duplicate a column's values into another column?

IE:

s_id  img_开发者_开发技巧id
1     -
2     -
3     -
4     -

to

s_id  img_id
1     1
2     2
3     3
4     4

---

UPDATE your_table SET img_id = s_id;