# Adding a table modifying the data I fetch

**URL:** <https://www.ruby-forum.com/t/adding-a-table-modifying-the-data-i-fetch/149991>\
**Category:** Rails\
**Created:** [October 2, 2008, 12:41am UTC](https://www.ruby-forum.com/t/adding-a-table-modifying-the-data-i-fetch/149991 "2008-10-02T00:41:39Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Norm](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/f475e1/32.png) [@Norm](https://www.ruby-forum.com/u/Norm)\
**Post date:** [October 2, 2008, 12:41am UTC](https://www.ruby-forum.com/t/adding-a-table-modifying-the-data-i-fetch/149991/1 "2008-10-02T00:41:39Z")

</div>

I have been writing software for a while but until now have managed to  
avoid almost any connection with sql and now I think I have a sql  
problem. I have written and released a FOSS Campground Reservation  
System ([http://open-campground.rubyforge.com](http://open-campground.rubyforge.com)) and I am having a problem  
with a new feature I want to incorporate.

In the system I have a reservations table which refers to a spaces table  
which refers to a price table which contains the rates (daily, weekly  
etc.) which vary depending on the features of the spaces. When I want a  
rate associated with a space I can simply do @space.price.daily\_rate and  
there we have it. Simple. Now I have a request to change the system so  
that I can have differing rates for different times like winter rates  
and summer rates and holiday rates etc.

The tables currently look like this (many details omitted):

create\_table “reservations”, :force =\> true do |t|  
t.column “space\_id”, :integer, :default =\>  
0, :null =\> false  
# … (a lot of unrelated details of the reservation)  
end

create\_table “spaces”, :force =\> true do |t|  
t.column “name”, :string, :limit =\> 24, :default =\>  
“”, :null =\> false  
# each space may refer to a different price or many may refer to a  
single price  
t.column “price\_id”, :integer, :limit =\> 3, :default =\>  
0, :null =\> false  
# … (a lot of unrelated details of the space like size and  
equipment)  
end

create\_table “prices”, :force =\> true do |t|  
# name is for administrative convenience only  
t.column “name”, :string, :limit =\> 24, :default =\> “”,  
:null =\> false  
t.column “daily\_rate”, :integer, :limit =\> 5, :default =\> 0,  
:null =\> false  
t.column “weekly\_rate”, :integer, :limit =\> 5, :default =\> 0,  
:null =\> false  
t.column “monthly\_rate”, :integer, :limit =\> 6, :default =\> 0,  
:null =\> false  
end

I have come up with a season table which includes the start and end  
dates and a name along with a method that returns the season for a  
reservation given the dates. I am trying to understand how I can  
shoehorn this concept into my system. I want to be able to, in a simple  
manner, retrieve the rate applicable to a given space during a given  
season. I know I will have to modify the prices in some manner to  
identify the association of price to season but how do I tie it all  
together?

Thanks for any help  
Norm