如何计算5天的总价格（mysql）酒店预订系统

这是查询：

select sum(coalesce(prices.room_price , def.room_price) ) as TotalPricefrom (select strtodate('2013-01-07' , '%Y-%m-%d') as thedate union all      select strtodate('2013-01-08' , '%Y-%m-%d') as thedate     ) dates left outer join     ts_room_prices prices     on dates.thedate between prices.season_start and prices.season_end and        dayname(dates.thedate) = prices.dayofweek join ts_room prices def    on def.season_name = 'default' and       def.hotel = <whatever the hotel is> and       def.dayofweek = dayname(dates.thedate)

注意，

sum()

请记住，您必须将所有日期与组合在一起放入初始子查询中

union all