For sorting in ascending order numbers which are written in text or characters:-
mysql> select number from (table) order by number;
+--------+
| number |
+--------+
| 1 |
| 10 |
| 2 |
| 3 |
| 4 |
| 5 |
| 6 |
| 7 |
| 8 |
| 9 |
+--------+

Use this:

We can use field_functions from mysql for custom sort or Can use CASE, IF,ELSE functionalities in mysql.
i.e:
ORDER BY CASE
WHEN `col` = 'item' THEN 1
WHEN `col` = 'thing' THEN 2
WHEN `col` = 'stuff' THEN 3
WHEN `col` = 'boom' THEN 4
ELSE 5
END

Example:-
1)
SELECT link_path,mlid FROM `rts1_menu_links` order by CASE WHEN link_path="photos/upload" THEN 1 ELSE 5 END,link_path DESC
2)select id from products where id in (4,5,6,7,8,9) order by field(id,4,7,6,5,9,8)

SELECT id, start_date FROM iddt WHERE id IN
('109k7','s3x6','sxmns','wt57')