CONCAT Ordenado

[NSD]

Lo resolvi con esta funcion:

Código MySQL:

DROP FUNCTION IF EXISTS SORT;
DELIMITER |
CREATE FUNCTION SORT(inString TEXT) RETURNS TEXT
DETERMINISTIC
READS SQL DATA
BEGIN
  DECLARE delim CHAR(1) DEFAULT ',';
  DECLARE strings INT DEFAULT 0;
  DECLARE forward INT DEFAULT 1;
  DECLARE backward INT;
  DECLARE remain TEXT;
  DECLARE swap1 TEXT;
  DECLARE swap2 TEXT;
  SET remain = inString;
  SET backward = LOCATE(delim, remain);
  WHILE backward != 0 DO
    SET strings = strings + 1;
    SET backward = LOCATE(delim, remain);
    SET remain = SUBSTRING(remain, backward+1);
  END WHILE;
  IF strings < 2 THEN RETURN inString; END IF;
  REPEAT
    SET backward = strings;
    REPEAT
      SET swap1 = SUBSTRING_INDEX(SUBSTRING_INDEX(inString,delim,backward-1),delim,-1);
      SET swap2 = SUBSTRING_INDEX(SUBSTRING_INDEX(inString,delim,backward),delim,-1);
      IF  swap1 > swap2 THEN
        SET inString = TRIM(BOTH delim FROM CONCAT_WS(delim
        ,SUBSTRING_INDEX(inString,delim,backward-2)
        ,swap2,swap1
        ,SUBSTRING_INDEX(inString,delim,(backward-strings))));
      END IF;
      SET backward = backward - 1;
    UNTIL backward < 2 END REPEAT;
    SET forward = forward +1;
  UNTIL forward + 1 > strings
  END REPEAT;
RETURN inString;
END |
DELIMITER;
 

Se la usa asi:

Código MySQL:

SELECT SORT(CONCAT_WS(',', 5, 1, 6)) ordenada; -- 1,5,6
SELECT SORT(CONCAT_WS(',', campo1, campo2, campo3)) ordenada FROM tabla1;