如何计算5天（mysql）酒店预订系统的总价

Question

I have this table for the price of rooms with diffrent season ( high , low ) season

how can get total price for 5 days with diffrent days and diffrent season ..

look at this table

this is my command ( mysql ) I want to get the total price for 10 nights from 04-07-2013 to 11-07-2013

select sum(
case when dayname('2013-01-07') = 'Monday' then coalesce(prices.room_price , def.room_price) 
 when dayname('2013-01-07') = 'Sunday' then coalesce(prices.room_price , def.room_price) 

)as TotalPrice 
from (select strtodate('2013-01-07' , '%Y-%m-%d') as thedate 
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 cross join ts_room prices def on def.season_name = 'default'

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addition

I wrote this command but still dosen't work

select sum(coalesce(prices.room_price , def.room_price) ) as TotalPrice
from (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 = 3233 and
       def.dayofweek = dayname(dates.thedate)

Error: #1305 - FUNCTION saudihot_saudihotels.strtodate does not exist

Answer 1

Here is the query:

select sum(coalesce(prices.room_price , def.room_price) ) as TotalPrice
from (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)

Notice that the sum() expression is much simpler and the day of week is now in the joins. I also added the hotel condition for getting the default values -- this should be in the other query as well.

Remember that you have to put all the dates in the initial subquery, combined with union all .