is it possible to have distinct + concat within group_concat?

I have this开发者_Python百科, as part of a bigger query:

CAST( GROUP_CONCAT( c.fname) AS char ) AS fname
, CAST( GROUP_CONCAT( c.lname ) AS char ) AS lname

I want something like:

CAST( GROUP_CONCAT( DISTINCT concat(c.fname,' ',c.lname) ) AS char ) AS user

Means, first I want to concat first name and last name, and then use the distinct to check whether the same firstname / lastname combination is not getting repeated. Possible using mysql or should I have to do that after using php?

Thanks guys.

I made a test with some of my tables, and it worked for me:

SELECT GROUP_CONCAT(DISTINCT CONCAT(id,nombre)) FROM pre_departamento;