Código SQL [-]SELECT Apellidos, Referencia, Nif, Codigo, COALESCE(NullIf(Referencia, ''), NullIf(Nif, ''), NullIf(CAST(Codigo AS VARCHAR(10), '') )) FROM Persona ORDER BY 2,3,4,5
SELECT Apellidos, Referencia, Nif, Codigo, COALESCE(NullIf(Referencia, ''), NullIf(Nif, ''), NullIf(CAST(Codigo AS VARCHAR(10), '') )) FROM Persona ORDER BY 2,3,4,5