On Friday, August 30, 2013 6:53:13 AM UTC-7, Christian MICHON wrote: > Hi Jeremy, > > I'm trying to use Sequel models to tap into a MSSQL database view (not > under my control) and figure out the hierarchy of products I have to > extract. I'm not performing any SQL write, pure read out. My next plans > include eager extraction, regardless of the depth (this will be in another > thread after I fix this issue). > > This particular product view contains 79 columns, and I only care for 2 ( > product_id and name). When declaring the model, I've restricted the dataset > to only these 2 attributes. Working fine. > > The parent-child relation is stored in another table, I've modified my > model with a many_to_many association in order to grab subproducts. Working > fine. > > Yet, each element I get in the result contains the original 79 columns, > and not the 2 columns I defined in the model. How to go around this? > > Here's the code: please keep in mind tbl_products and tbl_sub_products are > actually views, not pure tables. > > class Product < Sequel::Model > set_dataset DB[:tbl_products].select(:product_id, :name) > set_primary_key :product_id > many_to_many :subproducts, :class=>self, :join_table=>:tbl_sub_products, > :left_key=>:product_id, :right_key=>:reference_product > end > > o = Product[82188] # => 2 attributes, all is good > o.subproducts.size #=> 3 subproducts, all is good > o.subproducts.map(&:product_id) #=> visual inspection of subproducts id, > many_to_many association is working well > o.subproducts # => kaboom: array of 3 Product objects, but each has a > @values of 79 attributes > > a = o.subproducts.first > a.class # => Product > a.columns # => [:product_id, :name] > a.instance_variable_get(:@values).size # => 79 > > Did I miss something obvious in the Sequel documentation? > > Thanks in advance for the help you can provide. >
many_to_many defaults to SELECTing associated_table.*. Use the :select association option to change which columns are selected. Thanks, Jeremy -- You received this message because you are subscribed to the Google Groups "sequel-talk" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sequel-talk. For more options, visit https://groups.google.com/groups/opt_out.
