As always, Fred, thanks for your reply. The example you give works until you include a join, then you get strings again.
Order.joins(:sales).group(:product_id).sum(:quantity) That returns strings again. I don't think I did anything AR shouldn't be aware of. BTW, the product_id is returned as a string too. I've verified that SQLite3 returns numbers for both. This really seems broken to me. Order has_many :sales Sale belongs_to :order Order has a ordered_at datetime and the seller_id, Sale has the product_id and quantity. This is why I need the join. (Oh, and Sale is actually LineItem/line_item, although I doubt that makes a difference.) d. On Jan 11, 1:14 pm, Frederick Cheung <[email protected]> wrote: > On Jan 11, 4:47 pm, IAmNan <[email protected]> wrote: > > > > > > > > > > > I wrote this question on RoRTalk back in August but haven't heard back > > yet:http://tinyurl.com/4ohxdnf. So I think I must've been unclear. > > > Assume you have a Sale model with just a product Id and a quantity > > sold. You want to see a total number of sales for each product. > > > Product.group(:product_id).select("product_id, sum(quantity) as > > total_quantity") > > > Let's collect just the totals to see what they look like in irb: > > Product.group(:product_id).select("product_id, sum(quantity) as > > total_quantity").map(&:total_quantity) > > > In SQLite (and MySQL I think) I get the following: > > => [293.00, 4.00, 76.00, 9.00, 370.25, 71.00] > > > BUT! PostgreSQL returns this: > > => ["293.00", "4.00", "76.00", "9.00", "370.25", "71.00"] > > > Strings! Why strings!? Am I doing something wrong? Why is this > > happening, how do I fix it, and why doesn't ActiveRecord protect poor > > little me from the mean world of db inconsistencies? ;) > > In general AR doesn't know the type of non column expressions. > If you did something like Product..group(:product_id).sum(:quantity) > then AR knows you're doing a sum, and it knows that the sum of > decimals should be decimals so it would cast what it got back from the > db to the appropriate type > > Fred > > > > > > > > > > > Thank in advance. > > PS Quantity is a decimal in the schema. -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
