Hi, I'm having great fun developing with Rails but I've come to a problem that I can't quite figure out. I have an Order object that "has_many" order_lines. This works perfectly and I can see all the lines. The OrderLine object has an order_id field as well as product_id and amount. Now ideally I would want to do : order.orderline.product.name for example to pull back the name of the product it's linking to - but no matter what I try, I cannot get that to work. Can anyone tell what I'm doing wrong? I imagine it's pretty obvious.... Thanks in advance!
on 2006-03-21 17:36
on 2006-03-21 17:41
Hmm... OrderLine "belongs_to" "products", right? Also: If you are doing a Order "has_many" "order_lines", you should call things this way: order.order_lines... instead of order.orderline...
on 2006-03-21 17:43
Oooh! I might know this. I'm just a beginner, but what I've done is something like this: Product.find(orderline.product_id).name Is there an easier way? Chris
on 2006-03-21 17:45
Hi, Sorry, I was using order_lines :) At present OrderLine belongs to Order
on 2006-03-21 18:23
If you have OrderLine model belongs_to :order ...then you'll be able to say: @the_order_line.order So, if you want to go the other way: @the_order.order_line ... you need the association in your Order class so that it knows. It doesn't look it the other models for associations that refer to it. Order model has_many :order_lines If you already have this, then you might try checking order, then orderlines, then product, then name. Maybe you're missing an association there somewhere. If that doesn't work, some detail about what you're actually getting would help. One other thing that helps me is the Rails console. You can interactively make an Order, test its lines, etc all without the continually save/refresh cycle of doing it in a web browser. --- Wes
on 2006-03-21 18:32
For what it's worth I haven't written much rails/ruby, I mostly lurk here ... but that said, Order has many OrderLines has many Products seems like your model and from what you've described, you're missing that final association ... I guess I'd also think OrderLines would have order_id, product_id and quantity ... while Products would have unit cost, description, etc ...
on 2006-03-21 18:38
Yes, that's what I've got the : order.orderlines bit works perfectly and I can do : order.orderlines.product_id which will give me the product id of a Product in the product table. But I want to do : order.orderlines.product which would point to the product in that line item. Is this possible?
on 2006-03-21 18:42
Just to correct myself ... it'd be Order has many OrderLines has one Product
on 2006-03-21 18:46
Does your OrderLine model have a "has_one Product" in it? ... that's what I think you're missing even if I'm not syntactically perfect;)
on 2006-03-21 20:16
Right, what Hank said, almost. You've got the Order model has_many :order_lines You know that it's working because you can get to the product_id, which is on the order line. Since you can't get to the product, you know that the OrderLine model doesn't know about the product. OrderLine model belongs_to :product You want belongs_to because the id for the product is in the order_lines table. Once you add that to the OrderLines model, you should be able to access a product from an order detail. If you haven't read this: http://api.rubyonrails.com/classes/ActiveRecord/As... ... it's got very good examples of when to use which association. -- Wes On 3/21/06, Hank M. <firstname.lastname@example.org> wrote: > > order.orderlines > > > > http://lists.rubyonrails.org/mailman/listinfo/rails > > > > > _______________________________________________ > Rails mailing list > email@example.com > http://lists.rubyonrails.org/mailman/listinfo/rails > > > -- -- Wes
on 2006-03-21 21:51
That's a handy link for the examples Wes ... I might have to actually start writing some of this stuff just for fun so I can better grok the syntax more naturally.
on 2006-03-22 17:33
Hi, When I try that I get this error : undefined method `assert_valid_keys' for :Product:Symbol I'm going to google for it now :)