# Update Realtion **URL:** \ **Category:** Rails\ **Created:** [June 8, 2010, 12:23pm UTC](https://www.ruby-forum.com/t/update-realtion/189822 "2010-06-08T12:23:12Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![mrwellmann](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/848f3c/32.png) [@mrwellmann](https://www.ruby-forum.com/u/mrwellmann)\ **Post date:** [June 8, 2010, 12:23pm UTC](https://www.ruby-forum.com/t/update-realtion/189822/1 "2010-06-08T12:23:12Z")
Hi I want to assign continents to my products with a drop down box. I managed to get everyting runing but now i have a probably quite easy to solve problem. I don’t get the update running. What want to do is basically: SELECT \* FROM “continents” WHERE (“continents”.“id” = “continent\_id”) LIMIT 1 But I don’t find the right syntax. At the moamnt it looks like this: SELECT \* FROM “continents” WHERE (id = ‘— :continend\_id’) LIMIT 1 The parameters of my update are looking like this: Parameters: {“commit”=\>“Update”, “action”=\>“update”, “\_method”=\>“put”, “authenticity\_token”=\>"\*\*\*", “product”=\>{“image\_url”=\>“w.jpg”, “expirience\_points”=\>“0”, “price”=\>“1”, “title”=\>“w”, “description”=\>“w”, “continent\_id”=\>“7”}, “id”=\>“11”, “controller”=\>“products”} This is the code of may update methode: def update @product = Product.find(params[:id]) @product.continent = Continent.find(:first, :conditions =\> [ “id = ?”,:continend\_id ]) if @product.update\_attributes(params[:product]) flash[:notice] = ‘Product was successfully updated.’ redirect\_to(@product) else render :action =\> “edit” end end ---
**Author:** ![mrwellmann](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/848f3c/32.png) [@mrwellmann](https://www.ruby-forum.com/u/mrwellmann)\ **Post date:** [June 8, 2010, 12:58pm UTC](https://www.ruby-forum.com/t/update-realtion/189822/2 "2010-06-08T12:58:05Z")
Hi Ma We, On Tue, Jun 8, 2010 at 5:23 AM, Ma We [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > @product.continent = Continent.find(:first, :conditions =\> [ “id = > ?”,:continend\_id ]) You haven’t posted what you’re getting as a result, but one problem is that you don’t have a variable named continend\_id in your code. You have a params element named continent\_id. Change the Continent.find clause to use :params[:continent\_id]. A couple of other tips. I always use .to\_i on finds where I’m using a param since they’re strings and find takes an integer. It helps to remind me that params are strings. Your Continent.find could be shortened to Continent.find(params[:continent\_id].to\_i) HTH, Bill ---
**Author:** ![mrwellmann](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/848f3c/32.png) [@mrwellmann](https://www.ruby-forum.com/u/mrwellmann)\ **Post date:** [June 8, 2010, 1:39pm UTC](https://www.ruby-forum.com/t/update-realtion/189822/3 "2010-06-08T13:39:51Z")
Thanks for your answer. I tried already: :params[:continent\_id] //Error: Couldn’t find Continent with ID=0 the problem is that :continent\_id is the foreign key in products and i’m looking for the :id in continents which is the same then :continent\_id I also tried to use: -:params[:continent\_id].to\_i //which comes out the same like :params[:continent\_id] -:continent\_id.to\_i //Error: Couldn’t find Continent with ID=103233 -:first, :conditions =\> [“id = ?”,:continend\_id.to\_i]) //the same then above except that it don’t brings the error because it just doesn’t find ID=103233 and returns nil The problem with :continent\_id.to\_i is that it is not casting the number value which should put in the case above 7 out. - @product.continent = Continent.find(:first, :conditions =\> [ “id = ?”,:continend\_id ]) //returns nil the SQL looks like this SELECT \* FROM “continents” WHERE (id = ‘— :continend\_id’) LIMIT 1 ---
**Author:** ![mrwellmann](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/848f3c/32.png) [@mrwellmann](https://www.ruby-forum.com/u/mrwellmann)\ **Post date:** [June 8, 2010, 1:48pm UTC](https://www.ruby-forum.com/t/update-realtion/189822/4 "2010-06-08T13:48:27Z")
Hi Marcus, On Tue, Jun 8, 2010 at 6:39 AM, Markus W. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Thanks for your answer. You’re welcome. > -:first, :conditions =\> [“id = ?”,:continend\_id.to\_i]) //the same then Are you sure it’s not just a typo? continend\_id vs continent\_id Best regards, Bill ---
**Author:** ![mrwellmann](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/848f3c/32.png) [@mrwellmann](https://www.ruby-forum.com/u/mrwellmann)\ **Post date:** [June 8, 2010, 2:12pm UTC](https://www.ruby-forum.com/t/update-realtion/189822/5 "2010-06-08T14:12:50Z")
You are right there was a typo but didn’t change anything. to make sure I tried :id.to\_i witch brings 3049 instead of 1 > > -:first, :conditions =\> [“id = ?”,:continend\_id.to\_i]) //the same then > > Are you sure it’s not just a typo? > > continend\_id vs continent\_id ---
**Author:** ![mrwellmann](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/848f3c/32.png) [@mrwellmann](https://www.ruby-forum.com/u/mrwellmann)\ **Post date:** [June 8, 2010, 3:22pm UTC](https://www.ruby-forum.com/t/update-realtion/189822/6 "2010-06-08T15:22:23Z")
Marnen Laibow-Koser wrote: > You’re trying to pass a symbol instead of a variable into your query > string, so of course it won’t work. What you want is > [“id = ?”, continent\_id.to\_i] (without the colon). > > But you should never need to do it this way. For a simple equality > check, use the hash syntax: > {:id =\> continent\_id.to\_i} > or consider find or find\_by\_id . Ok I do understand now the Problem with the Symbols. But with @product.continent = Continent.find({:id =\> continent\_id.to\_i}) I get undefined local variable or method `continent\_id’ waht I do understand because I’m in def update and the parameters witch are passed are: Parameters: {“commit”=\>“Upd… , “product”=\>{“image\_url”=\>”/images/Burger.png", “expirience\_points”=\>“10”, “price”=\>“1.99”, “title”=\>“WHOPPER®”, “description”=\>"…", “continent\_id”=\>“7”}, “id”=\>“1”, “controller”=\>“products”} But how do I get now from :product the “continent\_id”=\>“7” ---
**Author:** ![mrwellmann](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/848f3c/32.png) [@mrwellmann](https://www.ruby-forum.com/u/mrwellmann)\ **Post date:** [June 8, 2010, 2:38pm UTC](https://www.ruby-forum.com/t/update-realtion/189822/7 "2010-06-08T14:38:17Z")
Markus W. wrote: > You are right there was a typo but didn’t change anything. > to make sure I tried :id.to\_i witch brings 3049 instead of 1 > > > > -:first, :conditions =\> [“id = ?”,:continend\_id.to\_i]) //the same then You’re trying to pass a symbol instead of a variable into your query string, so of course it won’t work. What you want is [“id = ?”, continent\_id.to\_i] (without the colon). But you should never need to do it this way. For a simple equality check, use the hash syntax: {:id =\> continent\_id.to\_i} or consider find or find\_by\_id . > > Are you sure it’s not just a typo? > > > > continend\_id vs continent\_id ## Best, Marnen Laibow-Koser [http://www.marnen.org](http://www.marnen.org) removed\_email\_address@domain.invalid ---
**Author:** ![mrwellmann](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/848f3c/32.png) [@mrwellmann](https://www.ruby-forum.com/u/mrwellmann)\ **Post date:** [June 8, 2010, 4:32pm UTC](https://www.ruby-forum.com/t/update-realtion/189822/8 "2010-06-08T16:32:41Z")
The answer is Continent.find(params[:product][“continent\_id”]) in more Steps first=params[:product] second=first[“continent\_id”] Continent.find(secon) May be there is a better way as well but any way it works finally. thanks to for Helping to get on the right way! Markus W. wrote: in def update and the parameters witch > are passed are: > > Parameters: {“commit”=\>“Upd… , > “product”=\>{“image\_url”=\>”/images/Burger.png", > “expirience\_points”=\>“10”, “price”=\>“1.99”, “title”=\>“WHOPPER®”, > “description”=\>"…", “continent\_id”=\>“7”}, “id”=\>“1”, > “controller”=\>“products”} > > But how do I get now from :product the “continent\_id”=\>“7”