select meida.media_name,sum(net_xf.xioafei) as 消费
from meida left join net_xf on meida.media_id = net_xf.meidad_id
group by meida.media_name
from meida left join net_xf on meida.media_id = net_xf.meidad_id
group by meida.media_name
seleect m.media_name as '媒体名',sum(n.xioafei) as '消费金额'
from net_xf as n ,meida as m
where n.media_id = m.media_id
group by m.media_name