MySQL:排序 GROUP_CONCAT 值

In short: Is there any way to sort the values in a GROUP_CONCAT statement?

查询:

GROUP_CONCAT((SELECT GROUP_CONCAT(parent.name SEPARATOR " » ") 
FROM test_competence AS node, test_competence AS parent 
WHERE node.lft BETWEEN parent.lft AND parent.rgt 
  AND node.id = l.competence 
  AND parent.id != 1 
ORDER BY parent.lft) SEPARATOR "<br />\n") AS competences

我得到这一行:

工艺品 »细木工

SELECT student_name,
  GROUP_CONCAT(DISTINCT test_score ORDER BY test_score DESC SEPARATOR ' ')
  FROM student
  GROUP BY student_name;