SELECT 
	CASE 	WHEN v3.text IS NULL THEN v2.text 	ELSE Concat_ws('',
v2.text,
v3.text) 	end AS Capacidad
FROM 
	prueba.Productos pr 	JOIN datasource_ww_my.cds_atr a ON pr.ProdID = a.ProdID 	JOIN datasource_ww_my.cds_voces v ON a.atrid = v.id 	JOIN datasource_ww_my.cds_voces v2 ON a.valid = v2.id 
	LEFT JOIN datasource_ww_my.cds_voces v3 ON a.unitid = v3.id
WHERE 
	pr.CODIGO = '42055'
		AND 	a.atrid = 'A00062'