Hi, I know i can do this: if i have an ordeline i can do: customername=orderline.order.customer.name but can i also go the other way around? lets say i have a customer and i want to get a hold of all orderlines orderlines=customer.orders.orderlines would be great, but that doesn''t work is there a smart way to do this or do i have to use a plain sql query like: select customer from customers,orders,orderlines where customer.customer_id=orders.customer_id and orderline.order_id=order.order_id the above doesn''t look very rails-like, thefore i am asking..... Remco -- Posted via http://www.ruby-forum.com/. --~--~---------~--~----~------------~-------~--~----~ 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 rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk -~----------~----~----~----~------~----~------~--~---
Remco Hh <rails-mailing-list@...> writes:> orderlines=customer.orders.orderlines would be great, but that doesn''t > workThe problem is that customer.orders works, but returns a collection of orders. And a *collection* doesn''t have any orderlines. A good bet would be customer.orders.collect{|o| o.orderlines} which would collect the orderlines from all of the orders and return them. You''d end up with an array of arrays (this will only make sense in a fixed width font:) ------- order 1 ------- - order 2 - , ------------- order 3 ------------- [ [orderline1, orderline2], [orderline3], [orderline4, orderline5, orderline6] ] if you only want the orderlines then you can call customer.orders.collect{|o| o.orderlines}.flatten which will collapse the above into one big array. --~--~---------~--~----~------------~-------~--~----~ 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 rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk -~----------~----~----~----~------~----~------~--~---
Remco Hh wrote:> Hi, > I know i can do this: > if i have an ordeline i can do: > > customername=orderline.order.customer.name > > but can i also go the other way around? > lets say i have a customer and i want to get a hold of all orderlines > > orderlines=customer.orders.orderlines would be great, but that doesn''t > work > > is there a smart way to do this or do i have to use a plain sql query > like: > > select customer from customers,orders,orderlines where > customer.customer_id=orders.customer_id and > orderline.order_id=order.order_id > > the above doesn''t look very rails-like, thefore i am asking..... > > RemcoAs long as your associations are set up properly, you sure can do that. However not exactly the way you expect. customer.orders returns an array of orders, and an array does not have a ''orderlines'' method. You should access it like this instead customer.orders.each do |order| do_something_with(order) order.orderlines.each do |ol| do_something_else_with(ol) end end Or if you really want all the orderlines from all orders for a customer lumped together in one big array, you can do: orderlines = [] costomer.orders.each do |order| orderlines += order.orderlines end -- Posted via http://www.ruby-forum.com/. --~--~---------~--~----~------------~-------~--~----~ 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 rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk -~----------~----~----~----~------~----~------~--~---
On 8/31/06, Remco Hh <rails-mailing-list-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org> wrote:> > Hi, > I know i can do this: > if i have an ordeline i can do: > > customername=orderline.order.customer.name > > but can i also go the other way around? > lets say i have a customer and i want to get a hold of all orderlines > > orderlines=customer.orders.orderlines would be great, but that doesn''t > work >customer.orders.orderlines.find(:all) may do the trick? Isak --~--~---------~--~----~------------~-------~--~----~ 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 rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk -~----------~----~----~----~------~----~------~--~---
Thanks Gareth and Alex. I get this, but i don''t really like it because if you compare it with how i do it in the sql example, i only use one query with joines to get the results. In your examples you create a loop (iterator) which submits multiple queries so, if there is no other method, i think i''ll just use plain old mysql I was convinced rails had a better method... regards, remco Alex Wayne wrote:> Remco Hh wrote: >> Hi, >> I know i can do this: >> if i have an ordeline i can do: >> >> customername=orderline.order.customer.name >> >> but can i also go the other way around? >> lets say i have a customer and i want to get a hold of all orderlines >> >> orderlines=customer.orders.orderlines would be great, but that doesn''t >> work >> >> is there a smart way to do this or do i have to use a plain sql query >> like: >> >> select customer from customers,orders,orderlines where >> customer.customer_id=orders.customer_id and >> orderline.order_id=order.order_id >> >> the above doesn''t look very rails-like, thefore i am asking..... >> >> Remco > > As long as your associations are set up properly, you sure can do that. > However not exactly the way you expect. > > customer.orders returns an array of orders, and an array does not have a > ''orderlines'' method. You should access it like this instead > > customer.orders.each do |order| > do_something_with(order) > order.orderlines.each do |ol| > do_something_else_with(ol) > end > end > > Or if you really want all the orderlines from all orders for a customer > lumped together in one big array, you can do: > > orderlines = [] > costomer.orders.each do |order| > orderlines += order.orderlines > end-- Posted via http://www.ruby-forum.com/. --~--~---------~--~----~------------~-------~--~----~ 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 rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk -~----------~----~----~----~------~----~------~--~---
Remco Hh wrote:> Thanks Gareth and Alex. > > I get this, but i don''t really like it because if you compare it with > how i do it in the sql example, i only use one query with joines to get > the results. In your examples you create a loop (iterator) which submits > multiple queries > > so, if there is no other method, i think i''ll just use plain old mysql > I was convinced rails had a better method... > > regards, > > remcoYou can use eager loading to make so only one query is needed. class Customer has_many :orders, :include => :orderlines end This will put a LEFT OUTER JOIN in your SQL and fetch all associated orderlines along with the orders. Then customer.order.first.orderlines will not generate a query. -- Posted via http://www.ruby-forum.com/. --~--~---------~--~----~------------~-------~--~----~ 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 rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk -~----------~----~----~----~------~----~------~--~---
> so, if there is no other method, i think i''ll just use plain old mysql > I was convinced rails had a better method... >If you need the lines for for a given order, why not just do something like this: @order = @customer.orders.find(order_id, :include => :order_lines) That''ll use 1 query - the lines for that order will be accessible via @order.order_lines. Steve --~--~---------~--~----~------------~-------~--~----~ 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 rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk -~----------~----~----~----~------~----~------~--~---
Isak Hansen wrote:> On 8/31/06, Remco Hh <rails-mailing-list-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org> wrote: >> orderlines=customer.orders.orderlines would be great, but that doesn''t >> work >> > > customer.orders.orderlines.find(:all) may do the trick? > > > Isaki dont''t think this wil work..... -- Posted via http://www.ruby-forum.com/. --~--~---------~--~----~------------~-------~--~----~ 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 rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk -~----------~----~----~----~------~----~------~--~---
If you really want to NOT loop on the orders, you could do the
following:
orders = Customer.orders.collect{|o| o.id}
lines = OrderLine.find(:all, :conditions => [''order_id =
(?)'',orders])
-Lonnie
Remco Hh wrote:> Thanks Gareth and Alex.
>
> I get this, but i don''t really like it because if you compare it
with
> how i do it in the sql example, i only use one query with joines to get
> the results. In your examples you create a loop (iterator) which submits
> multiple queries
>
> so, if there is no other method, i think i''ll just use plain old
mysql
> I was convinced rails had a better method...
>
> regards,
>
> remco
--
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