La consulta es la sig
Código:
SELECT sum(estadistica.cant_conex) from estadistica where rdb not in (select rdb from estadistica where rdb = 2163 )and fecha BETWEEN '2008-09-22' AND '2008-09-22' UNION select sum(estadistica.cant_conex)FROM ESTADISTICA WHERE fecha BETWEEN '2008-09-22' AND '2008-09-22' and rdb = 2163