How to order strings format from database in PHP?

I have numbers like this: 666/2014, 01/2014, 1/2014, 02/2014, 125/2014, 06/2014 ...etc as STRING named 'n_inscription' in database. I want to retrieve those strings In ORDER from database

I used this:

$sql_students = $bd->query("SELECT * FROM `es_student_infos`
                            WHERE school_year='$school_year'
                            ORDER BY right(n_inscription, 4) * 1,
                            substring_index(n_inscription, '/', 1) * 1");

I get result like this: 01/2014, 02/2014, 06/2014, 1/2014, 125/2014, 666/2014

and the result I'm looking for is like this: 01/2014, 1/2014, 02/2014, 06/2014, 125/2014, 666/2014

any suggestion please?

Solution

The best approach is probably to normalize the input so normal sorting does what you want it to do. For example, store the student number and year in two separate INTEGER columns and then ORDER BY studentNumber ASC, inscriptionYear ASC.

If that's absolutely not possible:

SELECT
  *
FROM
  es_student_infos
ORDER BY
  CAST(RIGHT(n_inscription, 4) AS UNSIGNED) ASC,
  CAST(LEFT(n_inscription, LOCATE('/', n_inscription) - 1) AS UNSIGNED) ASC

Link to fiddle demonstrating the solution: http://sqlfiddle.com/#!2/a5538/1/0